Electron Microscopes:
Dr. Mohammad Najafi
PhD in Management | Electrical and Electronics Engineer | Specialist in Management and Engineering | Project Leader | Head of Engineering Department |
Electron microscopes are mainly divided into two types: Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). Each of these microscopes has specific features and applications, which are explained below:
### 1. Transmission Electron Microscope (TEM)
The Transmission Electron Microscope uses a beam of electrons to examine the internal structures of very thin samples.
- Working Principle: Electrons pass through the sample and are scattered by the atoms in the sample. The transmitted electrons are converted into an image by a system of magnetic lenses.
- Image Resolution: Very high (up to the resolution in the order of angstroms).
- Applications: Studying the internal structures of cells, viruses, nanostructured materials, and crystallography.
- Samples: Samples must be very thin (less than 100 nanometers).
### 2. Scanning Electron Microscope (SEM)
The Scanning Electron Microscope is used to study the surfaces of samples.
- Working Principle: A narrow electron beam scans the surface of the sample, producing secondary and backscattered electrons. These electrons are collected by detectors to create an image of the sample's surface.
- Image Resolution: Lower than TEM, but generally suitable for various applications (resolution in the nanometer range).
领英推荐
- Applications: Studying the surfaces of materials, identifying surface chemical composition, examining particle shape and size.
- Samples: Samples do not need to be thin sections and can be thick.
### Other Types of Electron Microscopes
In addition to TEM and SEM, there are other types of electron microscopes developed for specific applications:
- Scanning Transmission Electron Microscope (STEM): Combines TEM and SEM to provide more detailed study of nanometric structures.
- X-ray Electron Microscope: Uses X-rays instead of electrons to study samples.
- Scanning Tunneling Microscope (STM): Studies material surfaces at the atomic scale using electron tunneling.
These microscopes each have unique applications and capabilities that can be utilized depending on scientific and industrial needs.
#TransmissionElectronMicroscopy #SEM #ScanningElectronMicroscopy #Nanotechnology #Nanostructures #MaterialScience #Crystallography #CellBiology #VirusResearch #NanometerResolution #SurfaceAnalysis #SamplePreparation #ScientificResearch #MicroscopyTechniques #HighResolutionImaging #Nanoparticles #ElectronBeams #MicrostructureAnalysis