Impedance spectrum and magnetic properties of BiFe_(0.95)Ti_(0.05)O_3 ceramics

摘要

Multiferroic BiFe0.95Ti0.05O3 (BFTO) powders were synthesized by sol-gel method, and then compacted by spark plasmas sintering (SPS) at 650 degrees C. Analysis of structure and morphology suggested the formation of a distorted rhombohedral in BFTO ceramics with a homogeneous distribution in grain sizes. BFTO ceramics revealed electric homogenous properties verified from the plots of complex impedance versus frequency. The contribution of oxygen vacancies in the behaviors of dielectric and ac conductivity was analyzed. At high temperature (473 K), the dielectric relaxation and ac conductivity were mainly attributed to the motion of oxygen vacancies. Doping of Ti4+ in BiFeO3 ceramics showed a high remanent magnetization due to the structural evolution and the broken of the spiral magnetic ordering in BiFeO3 system.