中文摘要：

基于四轮马车免费精力的扩大提出的热力学的模型对包含 ferro/para-electric 转变的性质的研究受欢迎、很好适合，或接近它。确实，热力学，模型的力量从被导出的一般性质，允许一个有效模型基于简单功能的形式被构造，参数适合到实验，由传递机械学的复杂性。尽管有不确由于 uctuations 的疏忽，这条途径在 nanoscale 被证明铁电体的开发为最近的研究有效、强大。当免费精力的贡献不得不被合并说明去极领域，表面和另外的缺点的存在时，在一些重要工作的努力最近面对了许多挑战。与机械学的暗最小化这些问题，是首要的重要性包含的 electromagnetics，力学和热力学明确地并且与完整的自我一致性被说明为。它是重要的免费精力 nanoscale 铁电体系统功能，例如铁电体薄电影(FTF ) ， bilayers (FB ) ，超点阵(FS ) ， nanowires (FNW ) ， nanotubes (FNT ) 和通道连接(FTJ ) 等等，必须从第一个原则热力学地被导出。

英文摘要：

Thermodynamic models formulated based on the Landau free-energy expansion are popular and well suited to studies involving properties of the ferro/para-electric transition, or near it. Indeed, the general nature of thermodynamics, from which the strength of the model is derived, allows a valid model to be constructed based on simple functional forms with parameters fitted to experiments, by passing the mechanistic complexity. Despite inaccuracy due to the neglect of fluctuations, this approach has been proven effective and powerful for recent research development of ferroelectrics in nanoscale. Efforts in some important works have recently faced much challenge, when free-energy contributions have to be incorporated to account for the presence of depolarization fields, surfaces and other defects. To minimize the problems with mechanistic obscurity, it is of paramount importance that the electromagnetics, mechanics and thermodynamics involved are accounted for explicitly and with full self-consistency. It is important that the free-energy functional of nanoscale ferroelectric systems, such as ferroelectric thin films （FTF）, bilayers （FB）, superlattices （FS）, nanowires （FNW）, nanotubes （FNT） and tunneling junctions （FTJ） etc., must be derived thermodynamically from first principles.