This section contains an introduction to vacancies. Topics covered include:
- some different types of point defects in metallic crystals
- how the total free energy of a crystal depends on the concentration of vacancies
- how the equilibrium concentration of vacancies is that which gives rise to the minimum overall free energy
- a derivation for the equilibrium concentration of vacancies as a function of temperature.
Before you start this section, you should be familiar with the terms crystal, free energy, enthalpy, entropy, melting temperature and equilibrium.