1) CONTENTS:  Introduction  Construction  Working Principle  The Electron Gun And Condenser System  Image Producing & Recording System  TEM Applications  Advantages  Disadvantages 2) INTRODUCTION: A Transmission Electron Microscope (TEM) utilizes energetic electron beam to provide morphologic, compositional and crystallographic information on samples.TEM produce High-Resolution, 2D images. The first transmission electron microscope was invented in 1933 by Max Knoll and E. Ruska at the Technical College in Berlin. 3) CONSTRUCTION: Electron Gun – to produce electrons. Magnetic condensing lens - to condense the electrons and to adjust the spot size of the electron.The specimen is placed in between the condensing lens and the objective lens. The magnetic objective lens - to block the high angle diffracted beam. Aperture - eliminate the diffracted beam (if any) and in turn increases the contrast of the image.The magnetic projector lens - to achieve higher magnification. Fluorescent (Phosphor) screen – To record the image. 4)Working Principle: High voltage electron beam is transmitted through a specimen to form an image. Stream of electrons are produced by the electron gun and is made to fall over the specimen using the magnetic condensing lens.Electrons are made to pass through the specimen and the image is formed on the fluorescent screen. 5) The Electron Gun And Condenser System: 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. 6) Image Producing & Recording System: Air needs to be pumped out of the vacuum chamber, creating a space where electrons are able to move.The objective lens is used to produces a image and then further magnified by the projector lens. 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. Monochromatic image is recorded in fluorescent screen or by capturing the image digitally to display on a computer monitor,basically stored in a TIFF or JPEG format. 7)TEM Applications: It analyze structure, topographical, morphological, compositional and crystalline information. Can be used in semiconductor analysis and production and the manufacturing of computer and silicon chips. To identify fractures and damages. 8)Advantages: Powerful magnification . It can produce magnification as high as 1,00,000 times as that of the size of the object. Images are high-quality and detailed.They are easy to operate with proper training. 9)Disadvantages:  Large and very expensive.  Laborious sample preparation.  TEM require special housing and maintenance.  Samples are limited to those that are electron transparent. 10) Thank You

1. PRESENTATION ON
TRANSMISSION ELECTRON MICROSCOPE
PRESENTED BY:-
Bijit Kumar Nath
Roll No: 02, 1st Semester
M.Tech (Nanotechnology)
NEHU,Shillong-22

2. CONTENTS
 Introduction
 Construction
 Working Principle
 The Electron Gun And Condenser System
 Image Producing & Recording System
 TEM Applications
 Advantages
 Disadvantages
2

3.  A Transmission Electron Microscope (TEM) utilizes energetic electron
beam to provide morphologic, compositional and crystallographic
information on samples.
 TEM produce High-Resolution, 2D images.
 The first transmission electron microscope was invented in 1933
by Max Knoll and E. Ruska at the Technical College in Berlin.
3
INTRODUCTION

4.  Electron Gun – to produce electrons.
 Magnetic condensing lens - to condense the electrons and to
adjust the spot size of the electron.
 The specimen is placed in between the condensing lens and
the objective lens.
 The magnetic objective lens - to block the high angle diffracted
beam.
 Aperture - eliminate the diffracted beam (if any) and in turn
increases the contrast of the image.
 The magnetic projector lens - to achieve higher magnification.
 Fluorescent (Phosphor) screen – To record the image.
4
CONSTRUCTION

5. Working Principle
 High voltage electron beam is transmitted through a specimen to form an
image.
 Stream of electrons are produced by the electron gun and is made to fall over
the specimen using the magnetic condensing lens.
 Electrons are made to pass through the specimen and the image is formed on
the fluorescent screen.
5

6. The Electron Gun And Condenser
System
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.
6
Fig : Electron Gun Fig : Condenser Lens

7. Image Producing & Recording System
 Air needs to be pumped out of the vacuum chamber, creating a
space where electrons are able to move.
 The objective lens is used to produces a image and then further
magnified by the projector lens.
 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.
 Monochromatic image is recorded in fluorescent screen or by
capturing the image digitally to display on a computer monitor.
 basically stored in a TIFF or JPEG format.
7

8. TEM Applications
 It analyze structure, topographical, morphological, compositional and
crystalline information.
 Can be used in semiconductor analysis and production and the
manufacturing of computer and silicon chips.
 To identify fractures and damages.
8

9. Advantages
 Powerful magnification . It can produce magnification as high as 1,00,000
times as that of the size of the object.
 Images are high-quality and detailed.
 They are easy to operate with proper training.
9

10. Disadvantages
 Large and very expensive.
 Laborious sample preparation.
 TEM require special housing and maintenance.
 Samples are limited to those that are electron transparent.
10

11. Thank You