Point defect behavior in B2-type intermetallic compounds

Recent development of investigations for point defects formed in B2-type intermetallic compounds is overviewed through mainly the authors’ experimental work. From examination of the structural data, lattice constant, vacancy concentration and defect concentrations, it becomes clear that the traditional classification of point defect behavior in B2-type intermetallics into two types, ASD and TRD, is too simplified to understand their actual defect structure and behavior. Consequently, we believe that B2 alloys are commonly in the hybrid state. This is supported by thermodynamic calculations based on the hybrid defect model.