钛酸钡极性相变的简谐子软模图像  

Harmonon Soft Modes of Polar Phase Transition in a Barium Titanate

作　　者：范仰才[1] 李智强[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：《广东工业大学学报》2003年第4期1-4,共4页Journal of Guangdong University of Technology

摘　　要：用复合空间型方法,在自由边界条件下解出了钛酸钡有限尺寸晶体的简谐振动方程,发现许多简谐子软模.用这些软模花样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.理论表明铁电相变过程涉及屏蔽电荷的激发及其在界面的缓慢扩散,以最后得出各个电畴内部的均匀自发极化.By using the complex species methed, the harmonic vibrational modes in a finite BaTiO3 with free houndary are calculated. Many harmonon soft modes are found and they can be used to explain why that barium titanate crystal has a and c domain structures in ferroelectric phase transition while temperature rde-duces. 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：复合空间型方法 简谐子 软模 钛酸钡 铁电相变 均匀自发极化 简谐振动 晶格振动 

分 类 号：O733.1[理学—晶体学]