ELECTRICAL-PROPERTIES OF HIGH-TEMPERATURE OXIDES, BORIDES, CARBIDES, AND NITRIDES

High-temperature materials including oxides, borides, carbides, and ni trides encompass all types of conductors: metallic, semiconducting, an d ionic. Their electrical conductivities are generally very sensitive to impurities regardless of the type of conductor. For large band-gap materials, which includes most of the oxides, the conductivities at lo w temperatures are frequently dominated by impurities or dopants, and intrinsic conduction only becomes significant above a temperature whic h depends largely on the level of dopant, the band gap, and the defect structure of the base material. The borides, carbides, and nitrides o f transition metals are metallic conductors with conductivities and te mperature coefficients of resistivity comparable to that of their pare nt metals.