铌酸铅钡晶体及其低温相变  

LEAD-BARIUM NIOBATE CRYSTALS AND THEIR LOW TEMPERATURE PHASE TRANSITION

作　　者：钟维烈[1] 张沛霖[1] 赵焕绥[2] 李翠平[2] 陈焕矗[3] 宋永远[3] 

机构地区：[1]山东大学物理系 [2]山东大学实验中心 [3]山东大学晶体材料研究所

出　　处：《硅酸盐学报》1990年第6期512-517,共6页Journal of The Chinese Ceramic Society

摘　　要：对于铝酸铅钡(PBN)系统中三种不同组份的晶体,研究了300K至10K范围内的介电和热电性能。发现它们在约50-70K发生铁电-铁电相变。相变温度上下晶体点群分别为4mm和m。在4mm相中,自发极化沿[001]方向,在m相中,自发极化在m面内。在降温过程中通过相变时,自发极化从[001]方向发生微小的偏离,但仍保持在一个m面,其方向用四方相的指数表示为[hhl]。The dielectric and pyroelectric properties of three crystals with different composition in lead-barium niobate(PBN) system have been investigated in the temperature range from 300K to 10K. A ferro-ferroeleetric phase transition in these crystals is found to occur at 50—70K.The point groups above and below the transition temperature are Amm and m respectively.In the Amm phase, spontaneous polarization is in the [001] direction, while in the m phase, it lies in the m plane. When the crystal is cooled from the temperature above the transition temperature to that below it, the spontaneous polarization slightly deviates from the [001] direction but still remains in a mirror piane. In terms of the index of the tetragonal cell, the direction of the spontaneous polarization at low tempera ure can be represented by[hhl].

关 键 词：铌酸铅钡 铁电晶体 铁电 相变 

分 类 号：TM221[一般工业技术—材料科学与工程]