Electron microscopy students will learn to operate an electron microsope; they will study kinematical and dynamical diffraction theory; structure determination and will analyze lattice defects.
- Introducing the TEM. Revision of basic crystallography
- Electron scattering by atoms, unit cells, crystals. Bragg's law
- The Ewald sphere construction. Constructing and interpreting electron diffraction patterns. Crystal shape effects.
- The fresnal construction and image intensities.
- The Kinematic theory of diffraction imaging. Bend contours and thickness fringes.
- Dislocation and stacking faults. Images of imperfect crystals. Visibility criterion.
- Problems with the Kinematic theory.
- Multiple scattering - the Dynamical theory.
- Electron absorption and its effects on dynamical theory.
- Bloch waves. Dynamical theory and Schrodinger's equation.
- The optics of the TEM
- Electron guns, electron lenses, vacuum systems.
- Sample preparation for the TEM.
- Inelastic electron scattering - EELS and microanalysis
- Fluorescent Xray production. ALCHEMI effects
- The resolution limit of the TEM. The Contrast Transfer Function and the idea of phase imaging in the TEM.
- Lattice imaging, structure imaging
- Electron holography.
In the laboratory sessions you will learn how to align and run the TEM and take electron diffraction patterns and micrographs. You will both observe ready-made samples and practice sample preparation on selected specimens. By Spring Break you will have started on your Class Project. Your grade is determined from class assignments (40%), lab notebooks (25%), and project write-up (35%). There are no scheduled exams and no textbook is required.