Selected Definitions, Classification, and Notation of Defects

The defects of crystal structure - that is, aU types of irregularity ofanideal crystal lattice -can be classified based on their size and/or number of dimensions [9,15-19]  

Only the point defects are thermodynamically equilibrium defects. All others, which sometimes are referred to as biographical defects , depend on the prehistory of each sample - that is, on the method and conditions of preparation, heat treatments, and so on. Therefore, a thermodynamic approach can be applied basically for the point defects. 

---