钙钛矿结构极性相变的晶格动力学图像  

The Lattice Dynamics of Polar Phase Transition in a Perovskite

作　　者：范仰才[1] 陆夏莲[2] 李景德[2] 

机构地区：[1]广东工业大学应用物理系,广东广州510090 [2]中山大学物理系,广东广州510275

出　　处：《哈尔滨理工大学学报》2002年第6期12-13,共2页Journal of Harbin University of Science and Technology

摘　　要：在自由边界条件下解出了钙钛矿结构有限尺寸晶体的简谐振动方程,发现许多简谐振子软模.用这些软模说明了钛酸钡晶体冷却时发生具有a畴和c畴结构的铁电相变.理论表明,铁电相变涉及屏蔽电荷的激发及其在界面的缓慢扩散,最后达到各个电畴内部处于均匀自发极化状态.The soft modes in a finite perovskite with free boundary were calculated, and they can be used to explain why that barium titanate crystal has a and c domain structures in ferroelectric phase transition while temperature reduces. The theory indicates that the ferroelectric phase transition is involved in the excitation of screen charges and their slow diffusion on crystal surface till homogeneous spontaneous polarization in each domain is established.

关 键 词：钙钛矿结构 极性相变 晶格动力学图像 简谐振子 软模 钛酸钡晶体 铁电相变 

分 类 号：O733.1[理学—晶体学] TM223[一般工业技术—材料科学与工程]