PX262 - K4 - electrons in crystalline solids
- crystalline solids include metals, insulators and semiconductors
- in a crystal, the potential which describes an electron's interaction with the nuclei, and all the other electrons must also have the symmetry of the lattice
- recalling the free electron model as a simple model of a metal - it readily conducts
- for a more realistic crystalline potential, energy gaps open up
- if
lies in a gap, the system is an insulator