Properties of Electrons , their Interactions with Matter and Applications in Electron Microscopy

3. Elastic Interactions ........................ 5 3.1. Incoherent Scattering of Electrons at an Atom .................................................. 5 3.1.1. Basics ....................................... 5 3.1.2. Interaction cross-section and mean free path .................................... 5 3.1.3. Differential cross section .......... 7 3.1.4. Interaction volume .................... 7 3.2. Contrast Generation in the Electron Microscope ............................................. 8 3.2.1. Basics ....................................... 8 3.2.2. Bright field imaging ................. 9 3.2.3. Applications of high angle scattering .......................................... 10 3.3. Coherent Scattering of Electrons at a Crystal .................................................. 12 3.3.1. Basics ..................................... 12 3.3.2. Bragg equation ....................... 13 3.3.3. Electron diffraction ................ 14 3.3.4. Bragg contrast ........................ 15