Defect structure and materials 'hardening' in Fe_2O_3-doped [Bi_(0.5)Na_(0.5)]TiO_3 ferroelectrics

摘要

The effect of Fe_2O_3-doping on the defect structure and piezoelectric properties of [Bi_(0.5)Na_(0.5)]TiO_3 ceramics is studied by means of electron paramagnetic resonance spectroscopy. The results show that the Fe~(3+) functional centers are incorporated at the perovskite B-site, and clearly can be attributed to the formation of (Fe_(Ti)'-V_O~**)~* defect complexes with charge compensating oxygen vacancies. Correspondingly, they act as acceptors which promotes materials "hardening."