The document discusses the principle, construction, working, uses, and limitations of a transmission electron microscope (TEM). A TEM works by transmitting a beam of electrons through a specimen, producing a magnified image on a screen. It consists of an electron gun, magnetic condensing lenses to focus the electrons, and an objective lens where the specimen is placed. TEMs are used in fields like biology, material science, and nanotechnology to study cell structures, crystal properties, and nanostructures. However, TEMs also have limitations such as requiring thin sample layers and long analysis times.

1. PRESENTED BY:
B. ROAHAN (23MER035)
K. THANISH (23MER050)

2. CONTENT
PRINCIPLE
CONSTRUCTION
WORKING
USES
LIMITATIONS

3. PRINCIPLE :
A beam of electron is transmitted through the specimen. The electron beam coming out produces a magnified
image on the Fluorescent screen or on the photographic film. In order to get large magnification, magnetic
lenses of short focal lengths are used

4. CONSTRUCTION :
1. It consists of an electron gun to produce electrons
2. Magnetic condensing lens is used to condense the electrons and is
also used to adjust the size of the electron that falls on to the specimen
3.The specimen is placed in between the condensing lens and the objective
lens as shown

5. How does TEM work?
• An electron source at the top of the microscope emits electron that travels through a vacuum in the column
Of the microscope
• Electro magnetic lenses are used to focus the electrons into a very thin beam and this is then directed
through the specimen of interest

6. USES:
▪ Used in biological /medical research to investigate parts of cells and molecules.
▪ Used in material science to study the structure an the weaknesses of crystals
▪ Used in nano technology

7. LIMITATION:
▪ Even if due to certain features, like magnitude, spatial resolution type of information is obtained.
▪ TEM technique is preferred by analysts
▪ It also has certain Limitations such as long time required
▪ The complex cutting operations of sample in order to obtain very thin layers