Effect of Cobalt substitution on the structural, electrical and magnetic properties of BaTiO3 ceramics

摘要

Cobalt doped BaTiO (BaTiCoO) with x = 0, 5, 7.5, 10% have been synthesized by solid state reaction method and their structural, electrical and magnetic properties have been investigated. Structural characterization show that a multiphase ceramic containing both tetragonal and hexagonal structures are obtained for Co compositions from x = 5% to x = 10%. Ferroelectric and ferromagnetic properties have been observed in all the Co-doped BaTiO ceramics at room temperature. The ferromagnetic hysteresis loop at room temperature is due to the formation of oxygen vacancies and their associated exchange interaction. The saturation magnetization (M) was 0.010 emu/g for x = 5%. Further, at x = 7.5%, it decreases and again start increasing upto ~ 0.013 emu/g for x = 10% with Cobalt concentration. However, ferroelectric hysteresis loop (P-E) is deteriorated (lossy type) with the increase of Co concentration above x = 5%. The dielectric characterization with frequency has also been carried out for all samples. The dielectric constant decreases with increasing Cobalt concentration.