The document discusses scanning electron microscopy (SEM) and its components and applications. It describes:
1. The main components of an SEM include the electron column, specimen chamber, vacuum pumping system, and electronic control and imaging system.
2. SEM can be used to observe surface morphology and crystal structure at magnifications from 10-100,000x with surface resolution of 3-100nm. Backscattered electron detection allows differentiation of areas with different average atomic number.
3. Applications include failure analysis, function control, material characterization, and verification of crystal orientation and phase identification at the micrometer scale.
The document provides information about scanning electron microscopy (SEM). It begins by explaining that SEM uses a beam of electrons to examine objects at a very fine scale, allowing magnification over 10,000x. It then describes the major components of an SEM, including the electron gun, electromagnetic lenses, sample chamber, and electron collection system. The document discusses how SEM works by scanning a focused electron beam across the sample surface and detecting signals from electron-sample interactions. Key signals detected are secondary electrons, backscattered electrons, and X-rays, allowing examination of surface topography and elemental composition. Applications of SEM are then briefly mentioned.
This document provides an introduction to electron microscopy. It begins with fundamental concepts and then discusses the construction of transmission and scanning electron microscopes. It explains key differences between electron microscopes and optical microscopes, such as electrons having no visible wavelength. The document compares the similarities and differences between EM and LM, such as both having illumination, specimen, and imaging systems, but EM using magnetic lenses. It discusses electron-specimen interactions that EM can detect such as backscattered electrons, secondary electrons, Auger electrons, X-rays, and diffraction patterns. Finally, it covers high resolution EM and examples of discoveries it enabled.
Electron microscopes use a beam of electrons instead of light to examine objects at a very fine scale. Transmission electron microscopes (TEMs) were developed first and use a thin sample, while scanning electron microscopes (SEMs) were developed later and can examine thicker samples. TEMs use electromagnetic lenses to focus electrons that pass through a thin sample, allowing observation of sample structure and composition. The electron beam interacts with the sample through elastic and inelastic scattering. Magnetic lenses collimate scattered electrons to form diffraction patterns containing structural information.
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.
The document provides an overview of scanning electron microscopes (SEM). It discusses that SEMs produce high-resolution images by scanning a sample surface with a focused beam of electrons. The electrons interact with atoms in the sample to provide information about topography and composition. Key components of SEMs are described, including the electron gun, lenses, detectors, and vacuum chamber. SEMs can achieve higher magnification than light microscopes and provide information about surface features, morphology, composition and crystal structure at high magnifications. Sample preparation such as drying, mounting and coating are outlined to prepare non-conductive specimens for imaging.
This document provides an overview of electron microscopy techniques, specifically scanning electron microscopy (SEM). It begins with a comparison of light microscopes and electron microscopes, noting that electrons have a much shorter wavelength than visible light, allowing for higher resolution images. It then discusses the basic principles and components of SEM, including how the electron beam scans the sample surface and interacts with atoms to produce signals used to form images. Applications mentioned include materials science, nanotechnology, biology, and more. Overall, the document serves as an introduction to SEM, covering its historical development, instrumentation, imaging modes, and various uses.
The document provides information about scanning electron microscopy (SEM). It begins by explaining that SEM uses a beam of electrons to examine objects at a very fine scale, allowing magnification over 10,000x. It then describes the major components of an SEM, including the electron gun, electromagnetic lenses, sample chamber, and electron collection system. The document discusses how SEM works by scanning a focused electron beam across the sample surface and detecting signals from electron-sample interactions. Key signals detected are secondary electrons, backscattered electrons, and X-rays, allowing examination of surface topography and elemental composition. Applications of SEM are then briefly mentioned.
This document provides an introduction to electron microscopy. It begins with fundamental concepts and then discusses the construction of transmission and scanning electron microscopes. It explains key differences between electron microscopes and optical microscopes, such as electrons having no visible wavelength. The document compares the similarities and differences between EM and LM, such as both having illumination, specimen, and imaging systems, but EM using magnetic lenses. It discusses electron-specimen interactions that EM can detect such as backscattered electrons, secondary electrons, Auger electrons, X-rays, and diffraction patterns. Finally, it covers high resolution EM and examples of discoveries it enabled.
Electron microscopes use a beam of electrons instead of light to examine objects at a very fine scale. Transmission electron microscopes (TEMs) were developed first and use a thin sample, while scanning electron microscopes (SEMs) were developed later and can examine thicker samples. TEMs use electromagnetic lenses to focus electrons that pass through a thin sample, allowing observation of sample structure and composition. The electron beam interacts with the sample through elastic and inelastic scattering. Magnetic lenses collimate scattered electrons to form diffraction patterns containing structural information.
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.
The document provides an overview of scanning electron microscopes (SEM). It discusses that SEMs produce high-resolution images by scanning a sample surface with a focused beam of electrons. The electrons interact with atoms in the sample to provide information about topography and composition. Key components of SEMs are described, including the electron gun, lenses, detectors, and vacuum chamber. SEMs can achieve higher magnification than light microscopes and provide information about surface features, morphology, composition and crystal structure at high magnifications. Sample preparation such as drying, mounting and coating are outlined to prepare non-conductive specimens for imaging.
This document provides an overview of electron microscopy techniques, specifically scanning electron microscopy (SEM). It begins with a comparison of light microscopes and electron microscopes, noting that electrons have a much shorter wavelength than visible light, allowing for higher resolution images. It then discusses the basic principles and components of SEM, including how the electron beam scans the sample surface and interacts with atoms to produce signals used to form images. Applications mentioned include materials science, nanotechnology, biology, and more. Overall, the document serves as an introduction to SEM, covering its historical development, instrumentation, imaging modes, and various uses.
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.
Dielectric surface imaging using scanning electron microsopeVnAy Kris
this presentation includes the principle,construction of scanning electron microscope and the problems-solutions it faces when dielectric surfaces are imaged along with normal imaging
This document discusses different types of microscopes, focusing on electron microscopes. It describes how electron microscopes like transmission electron microscopes (TEM) and scanning electron microscopes (SEM) work using electron beams instead of light, allowing them to achieve much higher magnifications. TEMs transmit electron beams through thin samples to view internal structures, while SEMs scan surfaces with electron beams to produce 3D images. Electron microscopes are important tools for viewing viruses, cells, and other microscopic structures.
Scanning electron microscopy (SEM) uses a focused beam of electrons to generate high-resolution images of surfaces. The document provides an overview of SEM, including its principles, components, electron-sample interactions, and techniques like energy-dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD) for analyzing samples. Key points covered include how SEM works at higher resolutions than light microscopes, the various signals generated from electron-sample interactions that provide information about topology and composition, and operational parameters that influence resolution and image quality.
The document discusses the principles of operation of a scanning electron microscope (SEM). It describes how electrons interact with samples through elastic and inelastic scattering. Electron scattering can provide information about sample topography and composition. The document outlines the main components of an SEM, including the electron gun, electromagnetic lenses, detectors for secondary electrons, backscattered electrons and X-rays. It explains how SEMs form images using these detected signals.
X-rays are electromagnetic radiation that were discovered in 1895 by Wilhelm Roentgen. They are produced when electrons are accelerated and strike a metal target in an x-ray tube. There are two types of x-rays produced - bremsstrahlung x-rays and characteristic x-rays. Bremsstrahlung x-rays are produced when electrons are decelerated upon impact with the target nucleus. Characteristic x-rays are produced when an electron collision ejects an inner shell electron, causing an outer shell electron to fill the vacancy and release a photon. The x-ray tube contains a cathode, anode, and evacuated glass enclosure to precisely control the electron beam and produce x-rays, which have properties
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 summarizes the key components and operating principles of a scanning electron microscope (SEM). The SEM uses an electron beam to scan the surface of a sample to produce images. It can achieve high magnification from 10-300,000x. The electron beam interacts with the sample, producing various signals containing information about the sample's surface topography and composition. Secondary electrons are used to view morphology while backscattered electrons provide material contrast and composition data. X-rays emitted are used for elemental analysis.
The document discusses the scanning electron microscope (SEM). The SEM uses a focused beam of electrons to scan the surface of a sample and produce images with high magnification and resolution. It has several advantages over optical microscopes, including higher magnification, greater depth of field, and the ability to provide 3D images and determine sample composition. The SEM has many applications in science and industry such as structural analysis, measurements, and failure inspection. It provides valuable but has some limitations like requiring solid samples and being costly.
Electron microscopes use electrons instead of light to form magnified images of samples. They can achieve much higher resolutions than light microscopes due to electrons having much shorter wavelengths than visible light. The basic components of an electron microscope include an electron gun that produces the electron beam, electromagnetic lenses that focus the beam, detectors that detect signals from sample interactions, and vacuum systems to allow unimpeded beam travel. Scanning electron microscopes in particular scan samples with a focused electron beam to produce topographical images at magnifications up to 200,000x and resolutions down to 1-4 nm.
SEM is a type of electron microscope designed for directly studying the surfaces of solid objects, that utilizes a beam of focused electron of relatively low energy as an electron probe that is scanned in a regular manner over the specimen.
The SEM can use either backscattered or secondary electrons to form .pdfrushabhshah600
The SEM can use either backscattered or secondary electrons to form the image. Explain how
each of these classes of electrons is produced in the sample and briefly discuss how images
produced by these two techniques might differ. Why would you use one technique or the other in
examining a sample in an SEM?
Solution
A scanning electron microscope (SEM)
It is a type of electron microscope that produces images of a sample by scanning it with a
focused beam of electrons. The electrons interact with atoms in the sample, producing various
signals that contain information about the sample\'s surface topography and composition and that
can be detected. The electron beam is generally scanned in a raster scanpattern, and the beam\'s
position is combined with the detected signal to produce an image. SEM can achieve resolution
better than 1 nanometer. Specimens can be observed in high vacuum, in low vacuum, in wet
conditions (in environmental SEM), and at a wide range of cryogenic or elevated temperatures.
Detection of secondary electrons
The most common imaging mode collects low-energy (<50 eV) secondary electrons that are
ejected from the k-shell of the specimen atoms byinelastic scattering interactions with beam
electrons. Due to their low energy, these electrons originate within a few nanometers from the
sample surface.The electrons are detected by an Everhart-Thornley detector, which is a type of
scintillator-photomultiplier system. The secondary electrons are first collected by attracting them
towards an electrically biased grid at about +400 V, and then further accelerated towards a
phosphor or scintillator positively biased to about +2,000 V. The accelerated secondary electrons
are now sufficiently energetic to cause the scintillator to emit flashes of light
(cathodoluminescence), which are conducted to a photomultiplier outside the SEM column via a
light pipe and a window in the wall of the specimen chamber. The amplified electrical signal
output by the photomultiplier is displayed as a two-dimensional intensity distribution that can be
viewed and photographed on an analogue video display, or subjected to analog-to-digital
conversion and displayed and saved as a digital image. This process relies on a raster-scanned
primary beam. The brightness of the signal depends on the number of secondary electrons
reaching the detector. If the beam enters the sample perpendicular to the surface, then the
activated region is uniform about the axis of the beam and a certain number of electrons
\"escape\" from within the sample. As the angle of incidence increases, the \"escape\" distance of
one side of the beam will decrease, and more secondary electrons will be emitted. Thus steep
surfaces and edges tend to be brighter than flat surfaces, which results in images with a well-
defined, three-dimensional appearance. Using the signal of secondary electronsimage resolution
less than 0.5 nm is possible
Detection of backscattered electrons
Backscattered electrons (.
X-rays were discovered in 1895 by Wilhelm Röntgen. They are produced when high-energy electrons collide with a metal target in a vacuum tube. This causes the electrons to lose energy, emitting X-ray photons via two processes: bremsstrahlung and characteristic radiation. When X-rays interact with matter, they can undergo coherent scattering, photoelectric absorption, Compton scattering, or pair production depending on their energy and the material's atomic number. Higher atomic number materials are more likely to cause photoelectric absorption while lower energies favor coherent scattering.
Instrumentation presentation - Auger Electron Spectroscopy (AES)Amirah Basir
Group 5-AES
Normaizatul Hanissa Binti Hamdan
Amirah Binti Basir
-Introduction/Backgroud /History, fundamental/basic principle and
elaboration of the principle, related pictures, related
equations/expressions/derivations, components and it functions,
related models/brands, technologies and applications
1. Electron microscopy techniques like SEM and TEM use electrons accelerated to high energies to interact with and provide information about samples on the nanometer scale.
2. SEM can be used to provide information on surface topography, crystalline structure, chemical composition and electrical behavior of the top 1um of a sample through detection of signals like secondary electrons, backscattered electrons, and x-rays.
3. Different signals provide different types of information - secondary electrons provide topographic information at high resolution while backscattered electrons provide compositional information and can also provide crystallographic data through electron channeling effects.
Auger electron spectroscopy (AES) is an analytical technique used to analyze the surface chemistry of materials. It works by (1) removing a core electron from the sample using a high-energy electron beam, (2) causing an electron to fill the resulting vacancy and emit an Auger electron, and (3) analyzing the kinetic energy of the emitted Auger electrons to determine the elemental composition of the top 1-10 nanometers of the sample surface. AES can also be used to create depth profiles by combining it with argon ion sputtering to sequentially remove layers from the surface. Typical applications of AES include analyzing thin film layers, surface oxides, and corrosion processes.
electron scattering,SEM,TEM,tunnel effect and lensesKASHISHMANGAL2
it can give you the brief view about the effects and lense used for electron microscope i.e. SEM,TEM,electron scattering,tunnel effect,electrostatic lens and magnostatic lens
The document discusses various characterization techniques used to analyze nanomaterials. It begins by providing historical context on the origins of nanotechnology and then describes several microscopy and spectroscopy methods. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, small angle X-ray scattering, and scanning probe microscopy are some of the key techniques explained in the document.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
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.
Dielectric surface imaging using scanning electron microsopeVnAy Kris
this presentation includes the principle,construction of scanning electron microscope and the problems-solutions it faces when dielectric surfaces are imaged along with normal imaging
This document discusses different types of microscopes, focusing on electron microscopes. It describes how electron microscopes like transmission electron microscopes (TEM) and scanning electron microscopes (SEM) work using electron beams instead of light, allowing them to achieve much higher magnifications. TEMs transmit electron beams through thin samples to view internal structures, while SEMs scan surfaces with electron beams to produce 3D images. Electron microscopes are important tools for viewing viruses, cells, and other microscopic structures.
Scanning electron microscopy (SEM) uses a focused beam of electrons to generate high-resolution images of surfaces. The document provides an overview of SEM, including its principles, components, electron-sample interactions, and techniques like energy-dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD) for analyzing samples. Key points covered include how SEM works at higher resolutions than light microscopes, the various signals generated from electron-sample interactions that provide information about topology and composition, and operational parameters that influence resolution and image quality.
The document discusses the principles of operation of a scanning electron microscope (SEM). It describes how electrons interact with samples through elastic and inelastic scattering. Electron scattering can provide information about sample topography and composition. The document outlines the main components of an SEM, including the electron gun, electromagnetic lenses, detectors for secondary electrons, backscattered electrons and X-rays. It explains how SEMs form images using these detected signals.
X-rays are electromagnetic radiation that were discovered in 1895 by Wilhelm Roentgen. They are produced when electrons are accelerated and strike a metal target in an x-ray tube. There are two types of x-rays produced - bremsstrahlung x-rays and characteristic x-rays. Bremsstrahlung x-rays are produced when electrons are decelerated upon impact with the target nucleus. Characteristic x-rays are produced when an electron collision ejects an inner shell electron, causing an outer shell electron to fill the vacancy and release a photon. The x-ray tube contains a cathode, anode, and evacuated glass enclosure to precisely control the electron beam and produce x-rays, which have properties
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 summarizes the key components and operating principles of a scanning electron microscope (SEM). The SEM uses an electron beam to scan the surface of a sample to produce images. It can achieve high magnification from 10-300,000x. The electron beam interacts with the sample, producing various signals containing information about the sample's surface topography and composition. Secondary electrons are used to view morphology while backscattered electrons provide material contrast and composition data. X-rays emitted are used for elemental analysis.
The document discusses the scanning electron microscope (SEM). The SEM uses a focused beam of electrons to scan the surface of a sample and produce images with high magnification and resolution. It has several advantages over optical microscopes, including higher magnification, greater depth of field, and the ability to provide 3D images and determine sample composition. The SEM has many applications in science and industry such as structural analysis, measurements, and failure inspection. It provides valuable but has some limitations like requiring solid samples and being costly.
Electron microscopes use electrons instead of light to form magnified images of samples. They can achieve much higher resolutions than light microscopes due to electrons having much shorter wavelengths than visible light. The basic components of an electron microscope include an electron gun that produces the electron beam, electromagnetic lenses that focus the beam, detectors that detect signals from sample interactions, and vacuum systems to allow unimpeded beam travel. Scanning electron microscopes in particular scan samples with a focused electron beam to produce topographical images at magnifications up to 200,000x and resolutions down to 1-4 nm.
SEM is a type of electron microscope designed for directly studying the surfaces of solid objects, that utilizes a beam of focused electron of relatively low energy as an electron probe that is scanned in a regular manner over the specimen.
The SEM can use either backscattered or secondary electrons to form .pdfrushabhshah600
The SEM can use either backscattered or secondary electrons to form the image. Explain how
each of these classes of electrons is produced in the sample and briefly discuss how images
produced by these two techniques might differ. Why would you use one technique or the other in
examining a sample in an SEM?
Solution
A scanning electron microscope (SEM)
It is a type of electron microscope that produces images of a sample by scanning it with a
focused beam of electrons. The electrons interact with atoms in the sample, producing various
signals that contain information about the sample\'s surface topography and composition and that
can be detected. The electron beam is generally scanned in a raster scanpattern, and the beam\'s
position is combined with the detected signal to produce an image. SEM can achieve resolution
better than 1 nanometer. Specimens can be observed in high vacuum, in low vacuum, in wet
conditions (in environmental SEM), and at a wide range of cryogenic or elevated temperatures.
Detection of secondary electrons
The most common imaging mode collects low-energy (<50 eV) secondary electrons that are
ejected from the k-shell of the specimen atoms byinelastic scattering interactions with beam
electrons. Due to their low energy, these electrons originate within a few nanometers from the
sample surface.The electrons are detected by an Everhart-Thornley detector, which is a type of
scintillator-photomultiplier system. The secondary electrons are first collected by attracting them
towards an electrically biased grid at about +400 V, and then further accelerated towards a
phosphor or scintillator positively biased to about +2,000 V. The accelerated secondary electrons
are now sufficiently energetic to cause the scintillator to emit flashes of light
(cathodoluminescence), which are conducted to a photomultiplier outside the SEM column via a
light pipe and a window in the wall of the specimen chamber. The amplified electrical signal
output by the photomultiplier is displayed as a two-dimensional intensity distribution that can be
viewed and photographed on an analogue video display, or subjected to analog-to-digital
conversion and displayed and saved as a digital image. This process relies on a raster-scanned
primary beam. The brightness of the signal depends on the number of secondary electrons
reaching the detector. If the beam enters the sample perpendicular to the surface, then the
activated region is uniform about the axis of the beam and a certain number of electrons
\"escape\" from within the sample. As the angle of incidence increases, the \"escape\" distance of
one side of the beam will decrease, and more secondary electrons will be emitted. Thus steep
surfaces and edges tend to be brighter than flat surfaces, which results in images with a well-
defined, three-dimensional appearance. Using the signal of secondary electronsimage resolution
less than 0.5 nm is possible
Detection of backscattered electrons
Backscattered electrons (.
X-rays were discovered in 1895 by Wilhelm Röntgen. They are produced when high-energy electrons collide with a metal target in a vacuum tube. This causes the electrons to lose energy, emitting X-ray photons via two processes: bremsstrahlung and characteristic radiation. When X-rays interact with matter, they can undergo coherent scattering, photoelectric absorption, Compton scattering, or pair production depending on their energy and the material's atomic number. Higher atomic number materials are more likely to cause photoelectric absorption while lower energies favor coherent scattering.
Instrumentation presentation - Auger Electron Spectroscopy (AES)Amirah Basir
Group 5-AES
Normaizatul Hanissa Binti Hamdan
Amirah Binti Basir
-Introduction/Backgroud /History, fundamental/basic principle and
elaboration of the principle, related pictures, related
equations/expressions/derivations, components and it functions,
related models/brands, technologies and applications
1. Electron microscopy techniques like SEM and TEM use electrons accelerated to high energies to interact with and provide information about samples on the nanometer scale.
2. SEM can be used to provide information on surface topography, crystalline structure, chemical composition and electrical behavior of the top 1um of a sample through detection of signals like secondary electrons, backscattered electrons, and x-rays.
3. Different signals provide different types of information - secondary electrons provide topographic information at high resolution while backscattered electrons provide compositional information and can also provide crystallographic data through electron channeling effects.
Auger electron spectroscopy (AES) is an analytical technique used to analyze the surface chemistry of materials. It works by (1) removing a core electron from the sample using a high-energy electron beam, (2) causing an electron to fill the resulting vacancy and emit an Auger electron, and (3) analyzing the kinetic energy of the emitted Auger electrons to determine the elemental composition of the top 1-10 nanometers of the sample surface. AES can also be used to create depth profiles by combining it with argon ion sputtering to sequentially remove layers from the surface. Typical applications of AES include analyzing thin film layers, surface oxides, and corrosion processes.
electron scattering,SEM,TEM,tunnel effect and lensesKASHISHMANGAL2
it can give you the brief view about the effects and lense used for electron microscope i.e. SEM,TEM,electron scattering,tunnel effect,electrostatic lens and magnostatic lens
The document discusses various characterization techniques used to analyze nanomaterials. It begins by providing historical context on the origins of nanotechnology and then describes several microscopy and spectroscopy methods. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, small angle X-ray scattering, and scanning probe microscopy are some of the key techniques explained in the document.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
This presentation was provided by Racquel Jemison, Ph.D., Christina MacLaughlin, Ph.D., and Paulomi Majumder. Ph.D., all of the American Chemical Society, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
Gender and Mental Health - Counselling and Family Therapy Applications and In...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Level 3 NCEA - NZ: A Nation In the Making 1872 - 1900 SML.pptHenry Hollis
The History of NZ 1870-1900.
Making of a Nation.
From the NZ Wars to Liberals,
Richard Seddon, George Grey,
Social Laboratory, New Zealand,
Confiscations, Kotahitanga, Kingitanga, Parliament, Suffrage, Repudiation, Economic Change, Agriculture, Gold Mining, Timber, Flax, Sheep, Dairying,
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptxEduSkills OECD
Iván Bornacelly, Policy Analyst at the OECD Centre for Skills, OECD, presents at the webinar 'Tackling job market gaps with a skills-first approach' on 12 June 2024
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
5. General Uses:
•Mengamati permukaan pada M= 10-100000 X,
resolusi permukaan hingga kedalaman 3-100 nm
•Apabila ditambahkan dengan detektor
backscattered, SEM berfungsi untuk:(1)
mengamati grain boundaries pada sampel tanpa
etsa; (2)pengamatan daerah domain pada material
ferromagnetic, (3)evaluasi orientasi kristalografi
grain dengan diameter 2-10 m, (4)pengamatan
fasa lain akibat adanya perbedaan rerata grain
6. Examples of Aplication
• Pengamatan permukaan dengan perbesaran diatas
perbesaran mikroskop optik
• Pengamatan fracture surfaces dan perbedaan
kedalaman permukaan akibat etsa
• Penentuan orientasi kristalografi akibat preparasi
surface, individual grain, fasa presipitat dan
dendrite
7. • Identifikasi elemen kimia dalam ukuran mikron
pada bulk sample,eg; inclusi, fasa presipitate
• Evaluasi gradien komposisi kimia pada
permukaan bulk sample
• Pengamatan pada semikonduktor devices untuk
failure analysis, function control dan verifikasi
desain
Examples of Aplication
8. Sampel
• Form; solid ataupun liquid dengan tekanan
rendah(>10-3 torr atau 0.13 Pa)
• Size: dibatasi oleh kemampuan masing-masing
peralatan biasanya sample dengan luasan 15-20
cm2 atau ukuran 4-8 cm masih mungkin diamati
dengan SEM
• Preparation: standar metalografi berupa teknik
polishing dan etsa yang berlaku untuk material
konduktif. Untuk material non-konduktif biasanya
di-coating dengan lapisan tipis carbon, gold atau
gold alloy hingga ketebalan lapisan 400Å. Sampel
harus terhubung dengan holder biasanya
digunakan pasta perak. Sample harus terbebas dari
uap air, bahan pengotor organik dan minyak
9. Capabilities of related Techniques
• X-ray Diffraction: menyediakan informasi
kristalografi
• Mikroskop Optik: memberikan informasi
awal keadaan permukaan sampel
• Transmission electron microscopy:
memberikan informasi keadaan material
secara spesifik; dislokasi, small angle
boundari distribution and vacancy cluster.
10.
11. Kategori komponen dalam mikroskop elektron
1. Electron column
2. Specimen chamber
3. Vacuum pumping system
4. Electronic control and imaging system
13. A Thermionic Electron Gun functions in the following manner
1. An positive electrical potential is applied to the anode
2. The filament (cathode) is heated until a stream of electrons is produced
3. The electrons are then accelerated by the positive potential down the column
4. A negative electrical potential (~500 V) is applied to the Whenelt Cap
5. As the electrons move toward the anode any ones emitted from the filament's
side are repelled by the Whenelt Cap toward the optic axis (horizontal center)
6. A collection of electrons occurs in the space between the filament tip and
Whenelt Cap. This collection is called a space charge
7. Those electrons at the bottom of the space charge (nearest to the anode) can exit
the gun area through the small (<1 mm) hole in the Whenelt Cap
8. These electrons then move down the column to be later used in imaging
14. Parameter elektron gun
Brightness, yang menunjukkan fungsi
material filamen, suhu operasi dan tegangan.
LaB6 adalah material dengan nilai tertinggi
dimana nilainya 10-20 X lipat dibanding
tungsten
2
2
4
/ o
o
d
I
solidangle
area
current
15. • The Broers design utilizes a
tungsten coil wrapped around the
pointed end of a long (around 2 cm)
LaB6 rod. This design uses the heat
radiation and electron bombardment
from the tungsten coil to heat the
very end of the tip. The conduction
of heat through the cathode holder,
located at the other end of the rod,
helps to lessen the problems of the
reactivity of the material.
• Vogel proposed a short LaB6 rod
heated directly by passing a current
through the LaB6 rod, perpendicular
to the length of the rod. This is
accomplished by using rigid
electrical connectors that also
provide the support for the rod.
• In the design of Ferris et al.7, a short
LaB6 rod is supported by a ribbon or
strip through which an electrical
current is passed for heating. The
rod is heated by conduction from the
ribbon.
17. Backscattered Electrons:
Formation
Caused by an incident electron colliding with an atom in the specimen which is
nearly normal to the incident's path. The incident electron is then scattered
"backward" 180 degrees.
Utilization
The production of backscattered electrons varies directly with the specimen's atomic
number. This differing production rates causes higher atomic number elements to
appear brighter than lower atomic number elements. This interaction is utilized to
differentiate parts of the specimen that have different average atomic number. An
example is shown in the SEM output section, specifically the mechanically alloyed
specimen micrograph
18. Secondary Electrons:
Source
Caused by an incident electron passing "near" an atom in the specimen, near enough
to impart some of its energy to a lower energy electron (usually in the K-shell). This
causes a slight energy loss and path change in the incident electron and the
ionization of the electron in the specimen atom. This ionized electron then leaves
the atom with a very small kinetic energy (5eV) and is then termed a "secondary
electron". Each incident electron can produce several secondary electrons.
Utilization
Production of secondary electrons is very topography related. Due to their low
energy, 5eV, only secondaries that are very near the surface (<10nm) can exit the
sample and be examined. Any changes in topography in the sample that are larger
than this sampling depth will change the yield of secondaries due to collection
efficiencies. Collection of these electrons is aided by using a "collector" in
conjunction with the secondary electron detector. The collector is a grid or mesh
with a +100V potential applied to it which is placed in front of the detector,
attracting the negatively charged secondary electrons to it which then pass through
the grid-holes and into the detector to be counted.
19. Auger Electrons
Source
Caused by the de-energization of the specimen atom after a secondary electron is
produced. Since a lower (usually K-shell) electron was emitted from the atom
during the secondary electron process an inner (lower energy) shell now has a
vacancy. A higher energy electron from the same atom can "fall" to a lower energy,
filling the vacancy. This creates and energy surplus in the atom which can be
corrected by emitting an outer (lower energy) electron; an Auger Electron.
Utilization
Auger Electrons have a characteristic energy, unique to each element from which
it was emitted from. These electrons are collected and sorted according to energy
to give compositional information about the specimen. Since Auger Electrons have
relatively low energy they are only emitted from the bulk specimen from a depth
of <3
20. X-rays
Source
Caused by the de-energization of the specimen atom after a secondary electron is
produced. Since a lower (usually K-shell) electron was emitted from the atom
during the secondary electron process an inner (lower energy) shell now has a
vacancy. A higher energy electron can "fall" into the lower energy shell, filling the
vacancy. As the electron "falls" it emits energy, usually X-rays to balance the total
energy of the atom so it .
Utilization
X-rays or Light emitted from the atom will have a characteristic energy which is
unique to the element from which it originated. These signals are collected and
sorted according to energy to yield micrometer diameter) of bulk specimens limiting
the point-to-point comparisons available
21. Thin Specimen Interactions
Unscattered Electrons
Source
Incident electrons which are transmitted through the thin specimen without any
interaction occurring inside the specimen.
Utilization
The transmission of unscattered electrons is inversely proportional to the
specimen thickness. Areas of the specimen that are thicker will have fewer
transmitted unscattered electrons and so will appear darker, conversely the
thinner areas will have more transmitted and thus will appear lighter.
22. Elasticity Scattered electrons
Source
Incident electrons that are scattered (deflected from their original path) by atoms in
the specimen in an elastic fashion (no loss of energy). These scattered electrons are
then transmitted through the remaining portions of the specimen.
Utilization
All electrons follow Bragg's Law and thus are scattered according to
Wavelength=2*Space between the atoms in the specimen*sin(angle of scattering).
All incident electrons have the same energy(thus wavelength) and enter the
specimen normal to its surface. All incidents that are scattered by the same atomic
spacing will be scattered by the same angle. These "similar angle" scattered
electrons can be collated using magnetic lenses to form a pattern of spots; each spot
corresponding to a specific atomic spacing (a plane). This pattern can then yield
information about the orientation, atomic arrangements and phases present in the
area being examined.
23. Inelastically Scattered Electrons
Source
Incident electrons that interact with specimen atoms in a inelastic fashion, loosing
energy during the interaction. These electrons are then transmitted trough the rest of
the specimen
Utilization
Inelasticaly scattered electrons can be utilized two ways
•Electron Energy Loss Spectroscopy: The inelastic loss of energy by the incident
electrons is characteristic of the elements that were interacted with. These
energies are unique to each bonding state of each element and thus can be used
to extract both compositional and bonding (i.e. oxidation state) information on
the specimen region being examined.
•Kakuchi Bands: Bands of alternating light and dark lines that are formed by
inelastic scattering interactions that are related to atomic spacings in the
specimen. These bands can be either measured (their width is inversely
proportional to atomic spacing) or "followed" like a roadmap to the "real"
elasticity scattered electron pattern.
24.
25. Pemasangan detektor
This is an image of the broken surface
of a piece of metal, formed using
secondary electron imaging
This is a picture taken inside the sample
chamber. On the left of the secondary
detector is the lens, on the right is the
backscatter detector.
26. Pemasangan detektor
On the far left of the backscatter
detector is the lens, in the center is the
secondary detector. To collect
electrons, the backscatter detector
moves under the lens so the electron
beam can travel through the hole in its
center.
This is an image of an aluminum copper
alloy formed using backscattered
electron imaging. The light area is
mostly copper and the dark area is
mostly aluminum.
28. Sistem Detektor
• Detektor Secondary Electron (SE) untuk
menghasilkan gambar analisis struktur mikro,
analisis produk korosi, patahan, kegagalan
material
• Detektor Backscattered Electron (BSE) untuk
menghasilkan gambar topografi peta struktur
mikro yang gambarnya dibentuk dari perbedaan
nomor atom/densitas yang dikandung oleh bahan.
Daerah cuplikan dengan nomer atom yang lebih
tinggi akan terlihat relatif lebih terang daripada
daerah dengan nomer atom rendah
• Detektor sinar-x (SiLi) dan EDX/EDS untuk
analisis komposisi unsur yang terkandung dalam
orde micrometer dan pemetaan (distribusi unsur)
dalam suatu bahan