Vibronic Theory of Structural Phase Transitions and Displacive Ferroelectrics
Vibronic Theory of Structural Phase Transitions and Displacive Ferroelectrics
复制标题
结构相变和位移铁电体的振动理论
DOI：
10.1002/pssb.2221490102
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发表时间：
1988
影响因子：
1.6
通讯作者：
P. Konsin
中科院分区：
文献类型：
--
作者：
N. Kristoffel;P. Konsin
在本文中，位移结构相变的振动理论将被视为铁电体的微观理论。将指出一些相对较新的阐述，并提及一些正在发展的相关领域。微观理论的目的必须是揭示导致铁电相变的相互作用，并用与晶体结构的微观描述相对应的术语来解释铁电体的复杂性质。该描述有些任意，并且所提到的相互作用的含义取决于该描述的明确实现。在仅使用有关晶体结构式的信息精确解决问题的限度内，根本不会出现有关相变中驱动相互作用的问题。但这种方法显然太麻烦了，人们至少必须挑出晶体的电子和核（核心）子系统。根据晶格动力学理论，铁电性起源问题被简化为阐明导致软光学振动模式出现的机制，沿着该模式晶体失去其动态稳定性（考虑位移相变）。相应地，关于稳定相互作用、恢复新结构中的晶格平衡的性质的问题也出现了。这两种相互作用可以但不一定重合。为此，铁电相变是由软模式驱动的，并且动态损失
I n the present article, the vibronic theory of displacive structural phase transitions will be considered as the microscopic theory of ferroelectrics. Some relatively new elaborations will be pointed out and some developing related fields mentioned. The aim of the microscopic theory must be to reveal the interactions leading to the ferroclectric phase transition and to explain the complex of properties of ferroelectrics in terms corresponding to a microscopic description of the crystal structure. This description is somewhat arbitrary and the meaning of the interactions mentioned depends on the definite realization of this description. Within the limit where the problem is solved exactly by using only the information about the structural formula of the crystal no question about the driving interaction in a phase transition arises at all. But such an approach is apparently too cumbersome and one must at least single out the electronic and nuclear (core) subsystems of the crystal. In terms of the dynamical theory of crystal lattices the problem of the origin of ferroelectricity is reduced to the elucidation of the mechanism leading to the appearance of the soft optical vibration mode along which the crystal loses its dynamical stability (displacive phase transitions are considered). Correspondingly, the question about the nature of stabilizing interactions, restoring the lattice equilibrium in the new structure, arises as well. These two interactions may, but need not, coincide. To this exteiit the ferroelectric phase transition is driven by the soft mode with the loss of the dynamical
DOI：
10.1007/bf01303701
发表时间：
1986-01-01
期刊：
ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER
影响因子：
--
作者：
BEDNORZ, JG;MULLER, KA
通讯作者：
MULLER, KA