This document discusses transmission electron microscopy (TEM). TEM uses beams of electrons instead of light to image objects at a much higher resolution. TEM can image objects as small as a single column of atoms. It works by transmitting a beam of electrons through a thin sample. The electrons interact with the sample and are used to form a magnified image. TEM allows observation of nano-scale structures and can provide information about material composition and crystal structure.
Electron microscopes use a beam of electrons to examine objects on a very fine scale. There are two main types: transmission electron microscopes (TEM) allow study of inner structures by passing electrons through thin samples, while scanning electron microscopes (SEM) are used to visualize surfaces by scanning a focused electron beam over the sample. SEMs detect signals from electron interactions to construct digital images, and require vacuum and conductive samples mounted on stubs. They provide three-dimensional topographical and compositional information at high magnifications.
The document discusses the transmission electron microscope (TEM). It begins by providing a brief history and overview, explaining that TEM uses electrons rather than light to image specimens. It then describes the key components and working principles of TEM, including how it produces higher resolution images than light microscopes due to electrons' lower wavelength. Finally, it outlines some common applications of TEM in fields like materials science, biology, and manufacturing, and notes advantages like powerful magnification but also disadvantages like high costs and specialized training needs.
Principle of transmission electron microscope.naren
The document discusses the principles and workings of transmission electron microscopes (TEM). Key points:
- TEMs use electron beams instead of light to achieve much higher magnifications, allowing observation of objects as small as 0.2 nm.
- Electrons are emitted from a heated filament and accelerated through magnetic lenses, which focus the beam onto ultra-thin specimen sections.
- Interactions between electrons and the specimen create an image that is magnified and detected, allowing visualization of internal structures at high resolution.
- Proper sample preparation including fixation, dehydration and thin sectioning is crucial for TEM to work, as it requires specimens thin enough to be transparent to electrons.
This document provides an overview of transmission electron microscopy (TEM). It discusses the history and development of TEM, the theoretical background explaining why electron microscopes were needed, an explanation of TEM instrumentation including the electron gun, condenser lens, objective lens and screen. It also covers TEM sample preparation techniques and the types of information that can be obtained from TEM such as thickness, orientation, composition and bonding states. Finally, it notes some limitations of TEM including small sample size, challenges of interpreting 2D images of 3D samples, potential radiation hazards, and the need for very thin electron transparent samples.
Scanning electron microscopy (SEM) uses a scanning electron microscope to inspect specimen topographies at high magnifications. SEM works by focusing a beam of electrons onto a specimen, causing secondary electrons to dislodge and be collected to form an image. Magnifications can exceed 300,000x but most semiconductor applications require less than 3,000x. SEM is used to analyze defects on device surfaces. Transmission electron microscopy (TEM) works by transmitting an electron beam through a thin specimen. The electron intensity distribution behind the specimen is magnified and viewed on a screen or captured digitally. TEM provides higher resolution than SEM and is used to examine ultrastructures of biological specimens like mitochondria at high magnifications.
The document discusses the transmission electron microscope (TEM). It begins by explaining that a TEM uses a beam of electrons rather than light to produce highly magnified images of thin specimens. It then provides details on the history and development of the TEM. The body of the document describes the main components of a TEM, including the electron gun, image producing system, and image recording system. It explains how each component works and its role in producing a magnified image. Applications of the TEM in fields like biology and nanotechnology are also mentioned.
Electron microscopes use a beam of electrons to examine objects on a very fine scale. There are two main types: transmission electron microscopes (TEM) allow study of inner structures by passing electrons through thin samples, while scanning electron microscopes (SEM) are used to visualize surfaces by scanning a focused electron beam over the sample. SEMs detect signals from electron interactions to construct digital images, and require vacuum and conductive samples mounted on stubs. They provide three-dimensional topographical and compositional information at high magnifications.
The document discusses the transmission electron microscope (TEM). It begins by providing a brief history and overview, explaining that TEM uses electrons rather than light to image specimens. It then describes the key components and working principles of TEM, including how it produces higher resolution images than light microscopes due to electrons' lower wavelength. Finally, it outlines some common applications of TEM in fields like materials science, biology, and manufacturing, and notes advantages like powerful magnification but also disadvantages like high costs and specialized training needs.
Principle of transmission electron microscope.naren
The document discusses the principles and workings of transmission electron microscopes (TEM). Key points:
- TEMs use electron beams instead of light to achieve much higher magnifications, allowing observation of objects as small as 0.2 nm.
- Electrons are emitted from a heated filament and accelerated through magnetic lenses, which focus the beam onto ultra-thin specimen sections.
- Interactions between electrons and the specimen create an image that is magnified and detected, allowing visualization of internal structures at high resolution.
- Proper sample preparation including fixation, dehydration and thin sectioning is crucial for TEM to work, as it requires specimens thin enough to be transparent to electrons.
This document provides an overview of transmission electron microscopy (TEM). It discusses the history and development of TEM, the theoretical background explaining why electron microscopes were needed, an explanation of TEM instrumentation including the electron gun, condenser lens, objective lens and screen. It also covers TEM sample preparation techniques and the types of information that can be obtained from TEM such as thickness, orientation, composition and bonding states. Finally, it notes some limitations of TEM including small sample size, challenges of interpreting 2D images of 3D samples, potential radiation hazards, and the need for very thin electron transparent samples.
Scanning electron microscopy (SEM) uses a scanning electron microscope to inspect specimen topographies at high magnifications. SEM works by focusing a beam of electrons onto a specimen, causing secondary electrons to dislodge and be collected to form an image. Magnifications can exceed 300,000x but most semiconductor applications require less than 3,000x. SEM is used to analyze defects on device surfaces. Transmission electron microscopy (TEM) works by transmitting an electron beam through a thin specimen. The electron intensity distribution behind the specimen is magnified and viewed on a screen or captured digitally. TEM provides higher resolution than SEM and is used to examine ultrastructures of biological specimens like mitochondria at high magnifications.
The document discusses the transmission electron microscope (TEM). It begins by explaining that a TEM uses a beam of electrons rather than light to produce highly magnified images of thin specimens. It then provides details on the history and development of the TEM. The body of the document describes the main components of a TEM, including the electron gun, image producing system, and image recording system. It explains how each component works and its role in producing a magnified image. Applications of the TEM in fields like biology and nanotechnology are also mentioned.
The scanning electron microscope (SEM) uses a focused beam of electrons to generate high-resolution images of surfaces. SEMs can provide information about topography, morphology, and composition through detection of signals from electron interactions with the sample surface. There are two main types: transmission electron microscopes study inner structures while scanning electron microscopes are used to visualize surfaces. SEMs work by scanning a focused electron beam across the sample; electrons interact with atoms and produce signals containing surface and composition data. Proper sample preparation including cleaning, fixation, dehydration and coating with a conductive material is required for clear SEM imaging.
This document discusses two types of electron microscopes: transmission electron microscopes (TEM) and scanning electron microscopes (SEM). A TEM uses a beam of electrons to produce high-resolution images of the internal structure of thin specimens. A SEM scans a focused beam of electrons across a sample to generate 3D topographical images of surfaces. Both require fixing, dehydrating, and metal-coating specimens, as well as specialized equipment like electron guns, lenses, and detectors. These powerful microscopes have enhanced our understanding of cell and molecular structures at resolutions far beyond conventional light microscopes.
This document provides an overview of scanning electron microscopy (SEM). It discusses the basic principles and instrumentation of SEM, including how electron beams are used to generate images by interacting with sample surfaces. The document explains that SEM provides higher resolution than light microscopes and can be used to examine surface topography, morphology, composition, and crystallographic structure at nanometer to micrometer scales. It describes the major components of an SEM, including the electron gun, electromagnetic lenses, vacuum system, detectors for secondary electrons and backscattered electrons, and how these are used to scan samples and form images.
Electron microscopes were developed to overcome limitations of optical microscopes and achieve higher magnifications. Scanning electron microscopes (SEM) work by scanning a high-energy beam of electrons across a sample, detecting signals from interactions between electrons and the sample. SEM can reveal topography, morphology, composition, and other details. It was first developed in the 1930s but commercial instruments emerged in the 1960s. SEM is useful for examining surfaces of various materials and specimens.
The scanning transmission electron microscope (STEM) uses a finely focused electron beam that scans across the sample in a raster pattern. The STEM provides atomic resolution imaging and analysis through detectors like the EELS spectrometer, bright-field detector, and annular dark-field detector. Scan coils are used to scan the beam across the sample, while the condenser lens demagnifies the electron crossover point for high magnification imaging. The STEM has various applications in materials science and biology for characterizing nano- and atomic-scale structures.
The document discusses transmission electron microscopy (TEM) and tissue sample preparation for TEM analysis. TEM uses electron beams instead of light for higher magnification imaging. Tissue must be carefully prepared through chemical fixation, dehydration, resin infiltration and sectioning. Samples are fixed in chemicals like glutaraldehyde and osmium tetroxide to preserve structures. They are then dehydrated in ethanol, infiltrated with resin for embedding, and ultrathin sections are cut and stained for viewing under the TEM. This allows high resolution imaging of cell and tissue structures down to the nanometer level.
Transmission electron microscopy (TEM) uses an electron beam to produce highly magnified images of very small specimens. It works by passing electrons through a thin specimen, and its high resolution allows it to view structures as small as viruses. TEM consists of an electron gun, image producing system with lenses, and an image recording system. It has applications in fields like medicine, materials science, and nanotechnology for viewing cell structures, bacteria, and nanoparticles. TEM provides powerful magnification and high-quality images but is also expensive to operate and maintain.
Transmission electron microscopy provides high resolution images of ultrastructures down to the nanometer scale. Specimen preparation for TEM involves fixation, dehydration, embedding, sectioning, and staining. The document outlines the principles and instrumentation of TEM, including the electron source, lenses, detectors, vacuum system, and electrical system. TEM is useful for medical and biological research applications such as virus identification, vaccine development, and disease surveillance.
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is guided through an ultra thin specimen, interacting with the specimen as it passes through.An image is formed from the fundamental interaction of the electrons transmitted through the specimen; the image is magnified and focused onto an imaging device, such as a fluorescent screen, on a layer of photographic film, or to be observed by a sensor such as a CCD camera.
The document discusses microscopy and different types of microscopes. It begins by defining microscopy as the technology that makes small objects visible to the human eye using microscopes. It then describes different types of microscopes, focusing on light microscopes and electron microscopes. Electron microscopes use a beam of electrons rather than light, allowing them to achieve much higher magnifications and resolving power than light microscopes. The document discusses the basic components and working principles of transmission electron microscopes and scanning electron microscopes. It also covers sample preparation techniques, applications, limitations, and recent research using electron microscopy.
Transmission electron microscopy (TEM) uses a beam of electrons to image the internal structure of ultra-thin specimens. TEMs can achieve significantly higher resolutions than light microscopes due to the much shorter wavelength of electrons. Samples must be carefully prepared to be only a few hundred nanometers thick to be electron transparent. The electron beam is transmitted through the sample, interacting with it, and an image is formed from the transmitted electrons and magnified onto a viewing screen. TEM is widely used across various scientific fields including materials science, biology, and medicine.
The document discusses scanning electron microscopes (SEMs), which use focused beams of electrons to obtain high-resolution, three-dimensional images of samples. SEMs have higher magnification and resolving power than light microscopes. The document describes the key parts of an SEM, including the electron gun, vacuum chamber, lenses, sample chamber, and detectors. It also discusses sample preparation and the advantages and disadvantages of SEMs.
This document summarizes environmental scanning electron microscopy (ESEM). It discusses the history and development of ESEM, how ESEM works by using lower vacuum pressure than conventional SEMs, and its applications such as cultural heritage conservation and nano-behavior studies. The document also notes some limitations of ESEM such as reduced beam penetration and higher noise compared to conventional SEMs.
The document summarizes the key components and operating principles of a scanning electron microscope (SEM). It describes the electron gun that generates the electron beam, the condenser lenses that focus the beam, the scan coils that scan the beam across the sample, and various detectors that detect signals from the sample. It outlines applications in fields like biology, materials science, and forensics. Advantages include detailed imaging and versatile information from detectors, while disadvantages include high costs and specialized training required.
The document provides information about scanning electron microscopes (SEMs). It describes that SEMs produce images of samples by scanning them with a focused beam of electrons, and electrons interact with atoms in the sample providing information about surface topography and composition. Key components of SEMs are electron guns, condenser lenses, objective apertures, scan coils, detectors, and vacuum chambers. SEMs have various applications in science and industry for examining surface features, fractures, and compositions at high magnifications.
This document provides an overview of scanning electron microscopy (SEM). It discusses how SEM works by using a beam of electrons to examine objects at a very fine scale, with greater resolving power than light microscopes. The first SEM debuted in 1938. SEM can provide information about a sample's topography, morphology, composition, and crystal structure. Diagrams show the major components of an SEM, including the electron gun and various detectors. Imaging modes like secondary electron and backscattered electron are described. Applications and limitations of SEM are also summarized.
Electron microscopes use a beam of electrons to examine objects on a very fine scale. There are two main types: transmission electron microscopes, which allow study of inner structures, and scanning electron microscopes, which are used to visualize surface features. Scanning electron microscopes work by scanning a focused beam of electrons across a sample to detect signals emitted from interactions between the electrons and the sample. These signals provide information about the sample's topography, morphology, composition, and other characteristics at high magnifications.
This document provides an overview of scanning transmission electron microscopy (STEM). It discusses the history and components of STEM, including the field emission gun, electromagnetic lenses, apertures, specimen stage, vacuum system, and detectors. Specimen preparation techniques like ion milling and electrolytic thinning are described. STEM operates by rastering a focused electron probe across the sample, while different detectors collect transmitted and scattered electrons to form images. Bright field (BF) and annular dark field (ADF) modes are covered, with ADF providing greater atomic number contrast. Advantages of STEM over conventional TEM are also highlighted.
Transmission electron microscopy (TEM) uses a beam of electrons to examine objects at a very fine scale. TEM can image at a higher resolution than light microscopes due to the shorter wavelength of electron beams. In TEM, a beam of electrons is transmitted through an ultrathin specimen, interacting with the sample as it passes through. This interaction is used to form an image that is magnified and focused onto a screen, with resolutions down to fractions of a nanometer. TEM is widely used in materials science, biology, and medicine for examining nanostructures.
2018 HM-Transmission electron microscopeHarsh Mohan
The document discusses transmission electron microscopy (TEM). It begins by explaining that TEM uses a beam of electrons to produce high resolution images of specimens. TEM provides higher resolution than optical microscopes because electrons have shorter wavelengths than visible light. The document then describes the basic components and functioning of TEM, including how electromagnetic lenses are used to focus the electron beam onto thin specimen samples and form magnified images. Specimen preparation methods for TEM like chemical fixation and staining are also covered.
The scanning electron microscope (SEM) uses a focused beam of electrons to generate high-resolution images of surfaces. SEMs can provide information about topography, morphology, and composition through detection of signals from electron interactions with the sample surface. There are two main types: transmission electron microscopes study inner structures while scanning electron microscopes are used to visualize surfaces. SEMs work by scanning a focused electron beam across the sample; electrons interact with atoms and produce signals containing surface and composition data. Proper sample preparation including cleaning, fixation, dehydration and coating with a conductive material is required for clear SEM imaging.
This document discusses two types of electron microscopes: transmission electron microscopes (TEM) and scanning electron microscopes (SEM). A TEM uses a beam of electrons to produce high-resolution images of the internal structure of thin specimens. A SEM scans a focused beam of electrons across a sample to generate 3D topographical images of surfaces. Both require fixing, dehydrating, and metal-coating specimens, as well as specialized equipment like electron guns, lenses, and detectors. These powerful microscopes have enhanced our understanding of cell and molecular structures at resolutions far beyond conventional light microscopes.
This document provides an overview of scanning electron microscopy (SEM). It discusses the basic principles and instrumentation of SEM, including how electron beams are used to generate images by interacting with sample surfaces. The document explains that SEM provides higher resolution than light microscopes and can be used to examine surface topography, morphology, composition, and crystallographic structure at nanometer to micrometer scales. It describes the major components of an SEM, including the electron gun, electromagnetic lenses, vacuum system, detectors for secondary electrons and backscattered electrons, and how these are used to scan samples and form images.
Electron microscopes were developed to overcome limitations of optical microscopes and achieve higher magnifications. Scanning electron microscopes (SEM) work by scanning a high-energy beam of electrons across a sample, detecting signals from interactions between electrons and the sample. SEM can reveal topography, morphology, composition, and other details. It was first developed in the 1930s but commercial instruments emerged in the 1960s. SEM is useful for examining surfaces of various materials and specimens.
The scanning transmission electron microscope (STEM) uses a finely focused electron beam that scans across the sample in a raster pattern. The STEM provides atomic resolution imaging and analysis through detectors like the EELS spectrometer, bright-field detector, and annular dark-field detector. Scan coils are used to scan the beam across the sample, while the condenser lens demagnifies the electron crossover point for high magnification imaging. The STEM has various applications in materials science and biology for characterizing nano- and atomic-scale structures.
The document discusses transmission electron microscopy (TEM) and tissue sample preparation for TEM analysis. TEM uses electron beams instead of light for higher magnification imaging. Tissue must be carefully prepared through chemical fixation, dehydration, resin infiltration and sectioning. Samples are fixed in chemicals like glutaraldehyde and osmium tetroxide to preserve structures. They are then dehydrated in ethanol, infiltrated with resin for embedding, and ultrathin sections are cut and stained for viewing under the TEM. This allows high resolution imaging of cell and tissue structures down to the nanometer level.
Transmission electron microscopy (TEM) uses an electron beam to produce highly magnified images of very small specimens. It works by passing electrons through a thin specimen, and its high resolution allows it to view structures as small as viruses. TEM consists of an electron gun, image producing system with lenses, and an image recording system. It has applications in fields like medicine, materials science, and nanotechnology for viewing cell structures, bacteria, and nanoparticles. TEM provides powerful magnification and high-quality images but is also expensive to operate and maintain.
Transmission electron microscopy provides high resolution images of ultrastructures down to the nanometer scale. Specimen preparation for TEM involves fixation, dehydration, embedding, sectioning, and staining. The document outlines the principles and instrumentation of TEM, including the electron source, lenses, detectors, vacuum system, and electrical system. TEM is useful for medical and biological research applications such as virus identification, vaccine development, and disease surveillance.
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is guided through an ultra thin specimen, interacting with the specimen as it passes through.An image is formed from the fundamental interaction of the electrons transmitted through the specimen; the image is magnified and focused onto an imaging device, such as a fluorescent screen, on a layer of photographic film, or to be observed by a sensor such as a CCD camera.
The document discusses microscopy and different types of microscopes. It begins by defining microscopy as the technology that makes small objects visible to the human eye using microscopes. It then describes different types of microscopes, focusing on light microscopes and electron microscopes. Electron microscopes use a beam of electrons rather than light, allowing them to achieve much higher magnifications and resolving power than light microscopes. The document discusses the basic components and working principles of transmission electron microscopes and scanning electron microscopes. It also covers sample preparation techniques, applications, limitations, and recent research using electron microscopy.
Transmission electron microscopy (TEM) uses a beam of electrons to image the internal structure of ultra-thin specimens. TEMs can achieve significantly higher resolutions than light microscopes due to the much shorter wavelength of electrons. Samples must be carefully prepared to be only a few hundred nanometers thick to be electron transparent. The electron beam is transmitted through the sample, interacting with it, and an image is formed from the transmitted electrons and magnified onto a viewing screen. TEM is widely used across various scientific fields including materials science, biology, and medicine.
The document discusses scanning electron microscopes (SEMs), which use focused beams of electrons to obtain high-resolution, three-dimensional images of samples. SEMs have higher magnification and resolving power than light microscopes. The document describes the key parts of an SEM, including the electron gun, vacuum chamber, lenses, sample chamber, and detectors. It also discusses sample preparation and the advantages and disadvantages of SEMs.
This document summarizes environmental scanning electron microscopy (ESEM). It discusses the history and development of ESEM, how ESEM works by using lower vacuum pressure than conventional SEMs, and its applications such as cultural heritage conservation and nano-behavior studies. The document also notes some limitations of ESEM such as reduced beam penetration and higher noise compared to conventional SEMs.
The document summarizes the key components and operating principles of a scanning electron microscope (SEM). It describes the electron gun that generates the electron beam, the condenser lenses that focus the beam, the scan coils that scan the beam across the sample, and various detectors that detect signals from the sample. It outlines applications in fields like biology, materials science, and forensics. Advantages include detailed imaging and versatile information from detectors, while disadvantages include high costs and specialized training required.
The document provides information about scanning electron microscopes (SEMs). It describes that SEMs produce images of samples by scanning them with a focused beam of electrons, and electrons interact with atoms in the sample providing information about surface topography and composition. Key components of SEMs are electron guns, condenser lenses, objective apertures, scan coils, detectors, and vacuum chambers. SEMs have various applications in science and industry for examining surface features, fractures, and compositions at high magnifications.
This document provides an overview of scanning electron microscopy (SEM). It discusses how SEM works by using a beam of electrons to examine objects at a very fine scale, with greater resolving power than light microscopes. The first SEM debuted in 1938. SEM can provide information about a sample's topography, morphology, composition, and crystal structure. Diagrams show the major components of an SEM, including the electron gun and various detectors. Imaging modes like secondary electron and backscattered electron are described. Applications and limitations of SEM are also summarized.
Electron microscopes use a beam of electrons to examine objects on a very fine scale. There are two main types: transmission electron microscopes, which allow study of inner structures, and scanning electron microscopes, which are used to visualize surface features. Scanning electron microscopes work by scanning a focused beam of electrons across a sample to detect signals emitted from interactions between the electrons and the sample. These signals provide information about the sample's topography, morphology, composition, and other characteristics at high magnifications.
This document provides an overview of scanning transmission electron microscopy (STEM). It discusses the history and components of STEM, including the field emission gun, electromagnetic lenses, apertures, specimen stage, vacuum system, and detectors. Specimen preparation techniques like ion milling and electrolytic thinning are described. STEM operates by rastering a focused electron probe across the sample, while different detectors collect transmitted and scattered electrons to form images. Bright field (BF) and annular dark field (ADF) modes are covered, with ADF providing greater atomic number contrast. Advantages of STEM over conventional TEM are also highlighted.
Transmission electron microscopy (TEM) uses a beam of electrons to examine objects at a very fine scale. TEM can image at a higher resolution than light microscopes due to the shorter wavelength of electron beams. In TEM, a beam of electrons is transmitted through an ultrathin specimen, interacting with the sample as it passes through. This interaction is used to form an image that is magnified and focused onto a screen, with resolutions down to fractions of a nanometer. TEM is widely used in materials science, biology, and medicine for examining nanostructures.
2018 HM-Transmission electron microscopeHarsh Mohan
The document discusses transmission electron microscopy (TEM). It begins by explaining that TEM uses a beam of electrons to produce high resolution images of specimens. TEM provides higher resolution than optical microscopes because electrons have shorter wavelengths than visible light. The document then describes the basic components and functioning of TEM, including how electromagnetic lenses are used to focus the electron beam onto thin specimen samples and form magnified images. Specimen preparation methods for TEM like chemical fixation and staining are also covered.
The document describes and compares scanning electron microscopes (SEM) and transmission electron microscopes (TEM). SEMs produce images by scanning a sample's surface with an electron beam, while TEMs transmit an electron beam through a thin sample to form a magnified image. Both use electromagnetic lenses and electron beam interactions with samples, but SEMs detect signals from secondary electrons at the surface, while TEMs detect transmitted electrons. Key applications include nanotechnology, materials science, biology, and medicine.
Scanning and transmission electroscopy.pptxNirmal P J
This document provides information about the transmission electron microscope (TEM). It begins by explaining that a TEM uses electron beams to produce highly magnified images of incredibly thin samples, up to 10-50 million times magnification and less than 150nm thick. It describes the basic components and functioning of a TEM, including the electron gun, magnetic lenses, sample stage, imaging system, and detector. Key points are that TEMs allow viewing structures at the molecular level and have a resolution limit of 0.2 micrometers. The document also discusses applications in fields like virology and nanotechnology, and advantages like high magnification and quality images.
Materials characterization techniques are used to analyze the internal structure and properties of a material. Common techniques include microscopic analysis using optical microscopes, scanning electron microscopes, and transmission electron microscopes to visualize internal structure at different magnifications. Other techniques include chemical analysis using techniques like x-ray spectroscopy and diffraction to determine composition, and thermal analysis to examine properties under temperature changes. Characterization provides information on properties like structure, defects, composition, and thermal behavior.
This document provides an overview of various characterization techniques used for nanomaterials and nanostructures. It begins by explaining that characterization of nanostructures requires high sensitivity, accuracy, and atomic-level resolution. It then classifies characterization techniques as either chemical or structural characterization. The document goes on to describe several common tools used, including XRD, SEM, TEM, optical spectroscopy, SPM techniques like AFM and STM, and their basic working principles and applications in nanomaterial characterization.
The document provides information about electron microscopes. It discusses how electron microscopes work by using a beam of electrons instead of light to illuminate samples. This allows for higher magnifications and resolutions compared to light microscopes. It describes the key components of transmission electron microscopes and scanning electron microscopes, including the electron gun, electromagnetic lenses, sample stage, detectors, and vacuum system. It also explains how electron microscopes can be used to study thin sections and surface topography of samples at nanometer or micrometer scales.
The document discusses electron microscopes. It defines electron microscopes as microscopes that use accelerated electrons rather than light to illuminate samples. Ernst Ruska built the first electron microscope in 1931. The document describes the working principles of transmission electron microscopes and scanning electron microscopes, including how each forms images. It also outlines the key components and parts of electron microscopes, their applications, advantages, and limitations.
The document discusses electron microscopes and their components and operation. Electron microscopes use a beam of electrons instead of light to examine objects at a very fine scale. There are two main types - scanning electron microscopes (SEM) and transmission electron microscopes (TEM). SEMs produce higher resolution images than optical microscopes and work by scanning a focused beam of electrons across a sample. TEMs require electron-transparent samples and work by transmitting electrons through a sample to form an image. Both types of electron microscopes have advanced scientific understanding by allowing observation of microscopic structures.
The document describes the electron microscope, including transmission electron microscopes (TEM) and scanning electron microscopes (SEM). TEMs use electron beams to create higher magnification images of ultrathin samples. SEMs scan samples with electron beams to produce surface topography and composition images. Both require extensive sample preparation and produce detailed images of small objects through electromagnetic beam manipulation.
Transmission Electron Microscope (TEM), RESOLVING POWER, Scanning Electron Microscope, PRINCIPLE AND WORKING OF SEM, SEM SAMPLE PREPARATION, Limitations of Scanning Electron Microscopy (SEM), ADVANTAGES & DISADVANTAGES OF SEM, APPLICATIONS OF SEM, PRINCIPLE, AND WORKING OF TEM, SAMPLE PREPARATION FOR TEM, ADVANTAGES & DISADVANTAGES OF TEM, APPLICATIONS OF TEM, Differences between SEM and TEM.
Electron microscopes use a beam of electrons to examine objects at a very fine scale. There are two main types - transmission electron microscopes (TEM) and scanning electron microscopes (SEM). TEMs allow study of inner structures by transmitting electrons through thin samples, while SEMs visualize surface topography by scanning sample surfaces. Both have advanced biological and materials applications due to their high resolving power and ability to produce detailed images at the nanoscale level. Recent developments include aberration correction to further improve resolution.
The document discusses confocal and electron microscopy. It describes the components and working principles of the confocal microscope, including point illumination. Applications of confocal microscopy include biomedical sciences, cell biology, and pharmaceutical quality control. Electron microscopy uses electron beams instead of light. Transmission electron microscopes view thin specimens through which electrons can pass, while scanning electron microscopes scan surfaces with a focused electron beam. Both provide high magnification and resolution views of cells, molecules, and materials.
The document summarizes electron microscopes. It describes that Ernst Ruska invented the first electron microscope in 1931, which uses a beam of electrons instead of light to magnify objects. It has three main parts - an electron gun that generates electrons, electromagnetic lenses that focus the electron beam, and a specimen holder. Electron microscopes can magnify objects up to two million times, allowing visualization of structures at the nanoscale. There are two main types - transmission electron microscopes (TEM), which produce highly detailed images but require thin specimens, and scanning electron microscopes (SEM) which scan surfaces and provide 3D topographic information.
Electron microscopy provides high resolution imaging of nanoscale structures using electron beams. There are two main types: transmission electron microscopy (TEM) and scanning electron microscopy (SEM). TEM uses transmitted electrons to image ultra thin samples, allowing visualization of structures less than an angstrom in size. SEM scans a focused electron beam across a sample to generate topographical and compositional information from electron interactions within microns of the surface. Both techniques require specialized sample preparation and equipment to produce high quality images for research applications across biology, materials science, and other fields.
This document provides an overview of the working principle of a scanning electron microscope (SEM). It discusses key components of an SEM like the electron gun, condenser lenses, scan coils, objective lens, and detectors. It explains how SEM produces high-resolution images by scanning a focused beam of electrons across a sample. Secondary electrons and backscattered electrons are generated from sample-electron interactions and detected to form images. Factors affecting resolution, magnification and other imaging modes are also summarized. Advantages of SEM like high resolution and versatility are mentioned along with disadvantages like high cost, vacuum requirements and sample preparation needs.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
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The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
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solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
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Time Division Multiplexing (TDM) is a method of transmitting multiple signals over a single communication channel by dividing the signal into many segments, each having a very short duration of time. These time slots are then allocated to different data streams, allowing multiple signals to share the same transmission medium efficiently. TDM is widely used in telecommunications and data communication systems.
### How TDM Works
1. **Time Slots Allocation**: The core principle of TDM is to assign distinct time slots to each signal. During each time slot, the respective signal is transmitted, and then the process repeats cyclically. For example, if there are four signals to be transmitted, the TDM cycle will divide time into four slots, each assigned to one signal.
2. **Synchronization**: Synchronization is crucial in TDM systems to ensure that the signals are correctly aligned with their respective time slots. Both the transmitter and receiver must be synchronized to avoid any overlap or loss of data. This synchronization is typically maintained by a clock signal that ensures time slots are accurately aligned.
3. **Frame Structure**: TDM data is organized into frames, where each frame consists of a set of time slots. Each frame is repeated at regular intervals, ensuring continuous transmission of data streams. The frame structure helps in managing the data streams and maintaining the synchronization between the transmitter and receiver.
4. **Multiplexer and Demultiplexer**: At the transmitting end, a multiplexer combines multiple input signals into a single composite signal by assigning each signal to a specific time slot. At the receiving end, a demultiplexer separates the composite signal back into individual signals based on their respective time slots.
### Types of TDM
1. **Synchronous TDM**: In synchronous TDM, time slots are pre-assigned to each signal, regardless of whether the signal has data to transmit or not. This can lead to inefficiencies if some time slots remain empty due to the absence of data.
2. **Asynchronous TDM (or Statistical TDM)**: Asynchronous TDM addresses the inefficiencies of synchronous TDM by allocating time slots dynamically based on the presence of data. Time slots are assigned only when there is data to transmit, which optimizes the use of the communication channel.
### Applications of TDM
- **Telecommunications**: TDM is extensively used in telecommunication systems, such as in T1 and E1 lines, where multiple telephone calls are transmitted over a single line by assigning each call to a specific time slot.
- **Digital Audio and Video Broadcasting**: TDM is used in broadcasting systems to transmit multiple audio or video streams over a single channel, ensuring efficient use of bandwidth.
- **Computer Networks**: TDM is used in network protocols and systems to manage the transmission of data from multiple sources over a single network medium.
### Advantages of TDM
- **Efficient Use of Bandwidth**: TDM all
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1. NANO TECHNOLOGY
Dr.S.BENJAMIN FRANKLIN
Assistant Professor (Selection Grade)
Department of Mechanical Engineering
Sri Ramakrishna Institute of Technology
Coimbatore-10
2. Electron Microscopy Techniques
Introduction
•Electron Microscopes are scientific instruments that use a beam
of highly energetic electrons to examine objects on a very fine
scale.
•The main advantage of Electron Microscopy is the unusual short
wavelength of the electron beams, substituted for light energy.
•The wavelengths of about 0.005 nm increases the resolving
power of the instrument to fractions
3. Microscopy
incident upon the subject of study, and the subsequent
collection of this scattered radiation in order to build
up an image.
• Scanning probe microscopy involves the
interaction of a scanning probe with the surface or
object of interest.
• Main branches: optical, electron and scanning probe
microscopy.
• Optical and electron
diffraction, reflection, or
microscopy involves the
refraction of radiation
4. Optical microscopy - definition
• Optical or light microscopy involves passing visible
light transmitted through or reflected from the sample
through a single or multiple lenses to allow a
magnified view of the sample.
• The resulting image can be detected directly by the
eye, imaged on a photographic plate or captured
digitally.
• The single lens with its attachments, or the system of
lenses and imaging equipment, along with the
appropriate lighting equipment, sample stage and
support, makes up the basic light microscope.
7. Electron Microscopy
•Beams of
electrons are used
to produce images
•Wavelength of
electron beam is
much shorter than
light, resulting in
much higher
resolution
8. Types of Electron
Microscope
• Transmission Electron Microscope (TEM) uses a
wide beam of electrons passing through a thin sliced
specimen to form an image. This microscope is
analogous to a standard upright or inverted light
microscope
• Scanning Electron Microscope (SEM) uses focused
beam of electrons scanning over the surface of thick
or thin specimens. Images are produced one spot at a
time in a grid-like raster pattern.
9. Introduction
microscopy or CTEM) is a microscopy technique in which a
beam of electrons is transmitted through a specimen to form
an image.
• The specimen is most often an ultrathin section less than 100
nm thick or a suspension on a grid.
• An image is formed from the interaction of the electrons with
the sample as the beam is transmitted through the specimen.
• The image is then magnified and focused onto an imaging
device, such as a fluorescent screen, a layer of photographic
film, or a sensor such as a charge-coupled device.
• Transmission
sometimes
electron microscopy (TEM, also
conventional transmission
electron
10. • Transmission electron microscopes are capable of imaging at a
significantly higher resolution than light microscopes, owing
to the smaller de Broglie wavelength of electrons.
• This enables the instrument to capture fine detail—even as
small as a single column of atoms, which is thousands of times
smaller than a resolvable object seen in a light microscope.
• Transmission electron microscopy is a major analytical
method in the physical, chemical and biological sciences.
• TEMs find application in cancer research, virology, and
materials science as well as polluton, nanotechnology and
semiconductor research.
11.
12. Transmission Electron Microscopy (TEM)
sections of
•Ultrathin
specimens
•Light passes through
specimen, then an
electromagnetic lens, to
a screen or film
•Specimens may be
stained with heavy
metal salts
14. The principles of TEM
• Transmission electron microscopy uses high energy electrons
(up to 300 kV accelerating voltage) which are accelerated to
nearly the speed of light.
• The electron beam behaves like a wavefront with wavelength
about a million times shorter than lightwaves.
• When an electron beam passes through a thin-section
specimen of a material, electrons are scattered.
• A sophisticated system of electromagnetic lenses focuses the
scattered electrons into an image or a diffraction pattern, or a
nano-analytical spectrum, depending on the mode of
operation.
15. • Each of these modes offers a different insight about the
specimen. The imaging mode provides a highly magnified
view of the micro- and nanostructure and ultimately, in the
high resolution imaging mode a direct map of atomic
arrangements can be obtained (high resolution EM = HREM).
• The diffraction mode (electron diffraction) displays accurate
information about the local crystal structure. The
nanoanalytical modes (x-ray and electron spectrometry) tell
researchers which elements are present in the tiny volume of
material.
• These modes of operation provide valuable information for
scientists and engineers in search of stronger materials, faster
microchips, or smaller nanocrystals.
16. Parts of the machine
• The typical transmission electron
laboratory contains a machine
microscope
with these
components:
I.
II.
Electron gun
Electron column
III. Electro-magnetic lens system
IV. Detectors
V. Water chilling system
VI. Specimen/sample chamber
VII. Main control panel and operational controls
VIII. Image capture
17.
18. Electron gun
• The
generates
beam.
electron
the
It is
gun
electron
usually
positioned in the top of
the instrument column.
• The
within
emitter is seated
a cone-shaped
Wehnelt cylinder and the
beam travels out of the
small central hole shown
in the apex of the cone.
19. Electron column
• The electron column is made up of the gun assembly at the
top, a column filled with a set of electromagnetic lenses, the
sample port and airlock, and a set of apertures that can be
moved in and out of the path of the beam. The contents of the
column are under vacuum.
20. Electron lens
• Electron lenses are designed to act in a manner emulating that
of an optical lens, by focusing parallel electrons at some
constant focal distance.
• Electron lenses may operate electrostatically or magnetically.
The majority of electron lenses for TEM use electromagnetic
coils to generate a convex lens.
• The field produced for the lens must be radially symmetrical,
as deviation from the radial symmetry of the magnetic lens
causes aberrations such as astigmatism, and worsens spherical
and chromatic aberration.
• Electron lenses are manufactured from iron, iron-cobalt or
nickel cobalt alloys, such as permalloy.
21. These are selected for their magnetic properties, such
as magnetic saturation, hysteresis and permeability.
22. Detectors
• One of the most common detectors seen on a
transmission electron microscope is the x-ray energy
dispersive spectroscopy (EDS or EDX) system. This
typically involves a large dewar for liquid nitrogen
(to keep the detector cold), an arm on which the
equipment sits, and a solid state detector that
penetrates the column (arrow) so it is located near the
sample.
23. Apertures
• Apertures are annular metallic plates, through which electrons
that are further than a fixed distance from the optic axis may
be excluded. These consist of a small metallic disc that is
sufficiently thick to prevent electrons from passing through the
disc, whilst permitting axial electrons. This permission of
central electrons in a TEM causes two effects simultaneously:
firstly, apertures decrease the beam intensity as electrons are
filtered from the beam, which may be desired in the case of
beam sensitive samples. Secondly, this filtering removes
electrons that are scattered to high angles, which may be due
to unwanted processes such as spherical or chromatic
aberration, or due to diffraction from interaction within the
sample.
27. Transmission Electron Microscope (TEM)
Working Concept
• TEM works much like a slide projector.
• A projector shines a beam of light through (transmits) the
slide, as the light passes through it is affected by the structures
and objects on the slide.
• These effects result in only certain parts of the light beam
being transmitted through certain parts of the slide.
• This transmitted beam is then projected onto the viewing
screen, forming an enlarged image of the slide.
• TEMs work the same way except that they shine a beam of
electrons (like the light) through the specimen (like the slide).
• Whatever part is transmitted is projected
onto a phosphor screen for the user to see.
• A more technical explanation of typical TEMs workings is as
follows.
29. • The "Virtual Source" at the top represents the electron gun,
producing a stream of monochromatic electrons.
• This stream is focused to a small, thin, coherent beam by the
use of condenser lenses 1 and 2. The first lens (usually
controlled by the "spot size knob") largely determines the
"spot size"; the general size range of the final spot that
strikes the sample.
• The second lens (usually controlled by the "intensity or
brightness knob" actually changes the size of the spot on the
sample; changing it from a wide dispersed spot to a pinpoint
beam.
• The beam is restricted by the condenser aperture (usually
user selectable), knocking out high angle electrons (those far
from the optic axis, the dotted line down the center)
30. • The beam strikes the specimen and parts of it
are transmitted.
• This transmitted portion is focused by the
objective lens into an image
• The image is passed down the column
through the projector lenses, being enlarged
all the way.
• The image strikes the phosphor image screen
and light is generated, allowing the user to
see the image
39. Image Modes
• In TEM, absorption of electrons plays a very minor
role in image formation. TEM contrast relies instead
on deflection of electrons from their primary
transmission direction when they pass through the
specimen. The contrast is generated when there is a
difference in the number of electrons being scattered
away from the transmitted beam. There are two
mechanisms by which electron scattering creates
images: mass-density contrast and diffraction
contrast.
40. Mass-Density Contrast
• The deflection of electron scan result from interaction
between electrons and an atomic nucleus. Deflection
of an electron by an atomic nucleus, which has much
more mass than an electron, is like a collision
between a particle and a wall. The particle (electron)
changes its path after collision. The amount of
electron scattering at any specific point in a specimen
depends on the mass-density (product of density and
thickness) at that point. Thus, difference in thickness
and density in a specimen will generate variation in
electron intensity received by an image screen in the
TEM.
41. • The deflected electron with scattering angle larger than the α
angle (in the order of 0.01 radians) controlled by the objective
aperture will be blocked by the aperture ring. Thus, the
aperture reduces the intensity of the transmission beam as the
beam passes through it. The brightness of the image is
determined by the intensity of the electron beam leaving the
lower surface of the specimen and passing through the
objective aperture. The intensity of the transmitted beam (It) is
the intensity of primary beam (Io) less the intensity of beam
deflected by object (Id) in a specimen.
Specimen.
42.
43. Diffraction Contrast
• We can also generate contrast in the TEM by a diffraction
method.
• Diffraction contrast is the primary mechanism of TEM image
formation in crystalline specimens. Diffraction can be
regarded as collective deflection of electrons.
• Electrons can be scattered collaboratively by parallel crystal
planes similar to X-rays. Bragg’s Law, which applies to X-ray
diffraction, also applies to electron diffraction.
• When the Bragg conditions are satisfied at certain angles
between electron beams and crystal orientation, constructive
diffraction occurs and strong electron deflection in a specimen
results.
• Thus, the intensity of the transmitted beam is reduced
when the objective aperture blocks the diffraction beams,
similar to the situation of mass-density contrast.
44.
45. • Note that the main difference between the two contrasts is that the
diffraction contrast is very sensitive to specimen tilting in the
specimen holder but mass-density contrast is only sensitive to total
mass in thickness per surface area.
• The diffraction angle (2θ) in a TEM is very small (≤1◦) and the
diffracted beam from a crystallographic plane (hkl) can be focused
as a single spot on the back-focal plane of the objective lens. The
Ewald sphere is particularly useful for interpreting electron
diffraction in the TEM.
• When the transmitted beam is parallel to a crystallographic axis, all
the diffraction points from the same crystal zone will form a
diffraction pattern (a reciprocal lattice) on the back-focal plane. The
diffraction contrast can generate bright-field and dark-field TEM
images.
• In order to understand the formation of bright-field and dark-field
images, the diffraction mode in a TEM must be mentioned. A TEM
can be operated in two modes : the image mode and the diffraction
mode.
46.
47. Phase Contrast
• Both mass-density and diffraction contrasts are amplitude
contrast because they use only the amplitude change of
transmitted electron waves.
• A TEM can also use phase difference in electron waves to
generate contrast. The phase contrast mechanism, however, is
much more complicated than that of light microscopy. T
• he TEM phase contrast produces the highest resolution of
lattice and structure images for crystalline materials.
• Thus, phase contrast is often referred as to high resolution
transmission electron microscopy (HRTEM).
• Phase contrast must involve at least two electron waves that
are different in wave phase.
• Thus, we should allow at least two beams (the transmitted
beam and a diffraction beam) to participate in image formation
in a TEM.
48. • A crystalline specimen with a periodic lattice structure
generates a phase difference between the transmitted and
diffracted beams.
• The objective lens generates additional phase difference
among the beams.
• Recombination of transmitted and diffracted beams will
generate an interference pattern with periodic dark–bright
changes on the image plane because of beam interferences.
• An interference pattern is a fringe type that reveals the
periodic nature of a crystal.
• Theoretical interpretation of phase contrast images is
complicated, particularly when more than one diffraction spot
participates in image formation.
52. TEM Imaging
• A Transmission Electron Microscope produces a high-resolution, black and
white image from the interaction that takes place between prepared samples
and energetic electrons in the vacuum chamber.
• Air needs to be pumped out of the vacuum chamber, creating a space where
electrons are able to move.
• The electrons then pass through multiple electromagnetic lenses. These
solenoids are tubes with coil wrapped around them.
• The beam passes through the solenoids, down the column, makes contact
with the screen where the electrons are converted to light and form an
image.
• The image can be manipulated by adjusting the voltage of the gun to
accelerate or decrease the speed of electrons as well as changing the
electromagnetic wavelength via the solenoids.
• The coils focus images onto a screen or photographic plate.
53. • During transmission, the speed of electrons directly correlates to electron
wavelength; the faster electrons move, the shorter wavelength and the
greater the quality and detail of the image.
• The lighter areas of the image represent the places where a greater number
of electrons were able to pass through the sample and the darker areas
reflect the dense areas of the object.
• These differences provide information on the structure, texture, shape and
size of the sample.
• To obtain a TEM analysis, samples need to have certain properties. They
need to be sliced thin enough for electrons to pass through, a property
known as electron transparency.
• Samples need to be able to withstand the vacuum chamber and often
require special preparation before viewing.
• Types of preparation include dehydration, sputter coating of non-
conductive materials, cryofixation, sectioning and staining.
55. Advantages of TEM
• A Transmission Electron Microscope is an impressive
instrument with a number of advantages such as:
• TEMs offer the most powerful magnification, potentially over
one million times or more
• TEMs have a wide-range of applications and can be utilized in a
variety of different scientific, educational and industrial fields
• TEMs provide information on element and compound structure
• Images are high-quality and detailed
• TEMs are able to yield information of surface features, shape,
size and structure
• They are easy to operate with proper training
56. Disadvantages of TEM
• TEMs are large and very expensive
• Laborious sample preparation
• Potential artifacts from sample preparation
• Operation and analysis requires special training
• Samples are limited to those that are electron transparent, able to
tolerate the vacuum chamber and small enough to fit in the chamber
• TEMs require special housing and maintenance
• Images are black and white
Electron microscopes are sensitive to vibration and electromagnetic fields
and must be housed in an area that isolates them from possible exposure.
A Transmission Electron Microscope requires constant upkeep including
maintaining voltage, currents to the electromagnetic coils and cooling
water.