SEM vs TEM | Difference between SEM and TEM

This page compares SEM (Scanning Electron Microscope) vs TEM (Transmission Electron Microscope) and mentions difference between SEM (scanning electron microscope or microscopy) and TEM (transmission electron microscope or microscopy).

Introduction:
As we know Electron based microscopes are powerful tool for characterization of variety of materials. There are two main types of electron microscopes viz. SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope). In both of these techniques, electrons are used to acquire samples of the images.

Both of them have folowing modules or components.
➤Source of electrons
➤Lenses to control the electron beam
➤Electron apertures
➤Chamber to hold all the above under high vacuum conditions.

SEM | Scanning Electron Microscope or Microscopy

• SEM is based on scattered electrons.
• It uses set of coils to scan beam in raster like pattern.
• Scattered electrons in SEM produces image of the sample after microscope collects and counts the scattered electrons.
• SEM focuses on surface of the sample and its composition.
• SEM depicts the sample bit by bit.
• It provides 3D image.
• SEM magnification limit is about 2 million.
• SEM resolution is about 0.4 nanometers.
• Example: Image on TV monitor.

TEM | Transmission Electron Microscope or Microscopy

• TEM is based on transmitted electrons.
• In this method, electrons are passed through the sample before being collected.
• In TEM, electrons are directly pointed toward the sample.
• TEM seeks to see inside or beyond the surface of the sample.
• TEM depicts the sample as whole structure.
• It provides 2D image.
• TEM magnification limit is about 50 million.
• TEM resolution is about 0.5 Angstroms.
• Example: Image on fluorescent screen.

Following table summarizes core difference between SEM and TEM.

SEM	TEM
3-Dimensional Image	2-Dimensional Image
Beam formation	Direct Imaging
Magnification - 2 million	Magnification - 50 million
Resolution - 0.4 nm	Resolution - 0.5 A^o
Scans large areas	Scans thin samples
Limitations - conducting samples, charging effect	Limitations - magnetic samples

What is difference between or comparison between

Following links mention difference or comparison between various equipments and terms:
comparison between SPI and I2C
difference between PXI and PCI
Microscope vs Telescope
Amplitude Modulation vs Angle Modulation
difference between modem and router
Air Fuel Ratio Sensor vs O2 Sensor
Radiometer vs Spectrometer vs Spectroradiometer
Clamp meter vs digital multimeter
Colorimeter vs Spectrophotometer
difference between Prism and Grating
difference between Venturi meter and Orifice meter
difference between Lux and Lumens