Synthesis and characterization of Bi(NiTi)O

Saito, Hiroyuki; Kitada, Kazuya*; Kobune, Masafumi*; Adachi, Wataru*; Yazawa, Tetsuo*; Ishikawa, Kenya*; Hiranaga, Yoshiomi*; Cho, Yasuo*; Aoki, Katsutoshi

Ferroelectric lead zirconate titanate is widely used as integral parts of electrical devices due to the high dielectric and electromechanical properties. However, the toxicity of lead oxide results in serious environmental problems and hence alternative compounds free from lead are urgently under development. Since Bi ion has the same electronic structure as the Pb ions, Bi-containing perovskites are promising candidates for lead-free ferroelectric ceramics. Bi(NiTi), BNT, ceramic was synthesized using reagent-grade BiO, TiO and NiCOnHO as starting materials. A mixture of the starting materials was calcined in air and then grounded to fine powder to fill up densely a high-pressure reaction cell. The sample was initially compressed and successively heated on keeping constant pressure. The single-phase perovskite structure was formed. P-E hysteresis loop shows that the BNT ceramic is ferroelectric. A multi domain structure of the BNT ceramic was also measured by scanning nonlinear dielectric microscopy.