한국재료학회지 제27권 제3호 (p.144-148)

Bi 과잉에 따른 BiFeO3-BaTiO3 세라믹스의 압전 및 유전특성

Effect of Bismuth Excess on Piezoelectric and Dielectric Properties of BiFeO3-BaTiO3 Ceramics
키워드 :
BiFeO3-BaTiO3 system,Bi excess,strain,curie temperature,lead-free.

초록

The effects of an excess of Bi on the piezoelectric and dielectric properties of 0.60Bi1+xFeO3-0.40BaTiO3 (x = 0, 0.01, 0.03, 0.05, 0.07) were investigated. The ceramics were processed through a conventional solid state reaction method and then quenched after sintering at different temperatures in the range of 980~1070 oC. A single perovskite structure without any secondary phase was confirmed for all compositions and temperatures. It was found that excess Bi reduced the sintering temperatures, acted as a sintering aid and enhanced the properties in combination with quenching. Curie temperature (TC) was found to slightly increase due to the presence of excess Bi; electrical properties were also improved by quenching. At x = 0.03 and 1030 oC, remnant polarization (2Pr) was as high as 45.4 μC/cm2 and strain at 40 kV/cm was up to 0.176 %.