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钛酸钡 BaTiO3低温时的自发极化

蔡玉平, 宁如云, 韩代朝   

  1. 军械工程学院基础部, 石家庄 050003
  • 收稿日期:2005-11-21 修回日期:2006-04-20 出版日期:2007-01-20 网络出版日期:2007-01-20

Spontaneous Polarization of BaTiO3 at Low Temperatures

CAI Yu-Ping, NING Ru-Yun, HAN Dai-Zhao   

  1. Department of Basic Courses, Ordnance Engineering College, Shijiazhuang 050003, China
  • Received:2005-11-21 Revised:2006-04-20 Published:2007-01-20 Online:2007-01-20

摘要: 考虑到序参量的量子饱和, 从调整后的标准朗道势形式出发, 讨论了钛酸钡低温时的压强-温度相图. 低温时相边界是非线性的, 应考虑量子效应的影响. 饱和温度θs 用来表征量子影响的程度, 与重声子模影响相变的程度相联系.

关键词: 序参量, 朗道势, 自发极化, 钛酸钡

Abstract: The pressure-temperature phase diagram of BaTiO3 was investigated by using a modification of the standard Landau potential to take account of quantum saturation of the order parameter. At low temperatures, each phase boundary bends sharply down, and this non-linear behavior is associated with quantum mechanical effects. Saturation temperature θs characterizes the extent of quantum mechanical, and is related to the extent to which changes in the hard phonon modes influence the transition mechanism.

Key words: order parameter, Landau potential, spontaneous polarization, BaTiO3

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