Transmission Electron Microscopy

Syllabus

This course includes an introduction to the basic principles of electron microscopy with emphasis on scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The principles of electron microscopy and electromagnetic lenses are described.

A. Principles of the TEM

• Introduction to TEM

History of TEM. Electron vs. light microscopy.

• Electron Scattering and Diffraction

Coherent and incoherent scattering. Elastic and inelastic scattering.

• Optical Theory and Electron Lenses

Resolution. Electromagnetic lens. Electrostatic lens.

B. Design of the TEM

• Electron Guns and Electron lenses

Thermionic guns and field-emission guns (FEGs). Condenser, objective and projector lens. Apertures and diaphragms. Lens aberrations (spherical aberration, chromatic aberration and astigmatism). Depth of focus and depth of field.

• Imaging System

Electron detectors. Image recording.

• Vacuum Systems

Mechanical pump. Diffusion pump. Sputter-ion pump. Turbomolecular pump.

C. Other modes on TEM

• X-ray microanalysis

X-ray formation. Energy-dispersive X-ray spectroscopy.

• Electron diffraction

Atomic scattering factor. Diffraction by crystals and Bragg’s law. Camera length and camera constant. Producing the diffraction pattern.

D. Sample preparation

• Specimens’ preparation for materials science

Specimen support grids. Creating thin disks (Electropolishing, Ion Milling). Microtomy.

Learning Outcomes

• Introduction to the basic principles governing electron scattering and the operation of electromagnetic lenses.
• To prepare students to understand the basic principles that characterize the electron microscopy, electron scattering and diffraction, and imaging.

Recommended Bibliography

1. D.B. Williams, C.B. Carter, Transmission Electron Microscopy: A Textbook for Materials Science, Plenum Press, New York, 1996.
2. Brent Fultz, James M. Howe. Transmission Electron Microscopy and Diffractometry of Materials, 3rd Ed., Springer, Berlin, 2008