Thermal fluctuations and phase diagrams of the phase-field crystal model with pinning.
Thermal fluctuations and phase diagrams of the phase-field crystal model with pinning.
复制标题
DOI：
10.1103/physreve.78.031109
复制
发表时间：
2008-08
期刊：
影响因子：
--
通讯作者：
J. P. Ramos;E. Granato;C. Achim;S. Ying;K. Elder;T. Ala‐Nissila
中科院分区：
文献类型：
--
作者：
J. P. Ramos;E. Granato;C. Achim;S. Ying;K. Elder;T. Ala‐Nissila
我们研究了热涨落对最近引入的具有外部钉扎势的二维相场晶体模型的相图的影响。该模型提供了一个连续的描述钉扎晶格系统允许弹性变形和拓扑缺陷。我们引入了一个非保守的版本的模型，并确定作为一个功能的晶格失配和强度的钉扎电位的基态相图。Monte Carlo模拟用于确定相图作为温度的函数附近的相称的阶段。结果表明，丰富的相图与公度，非公度，和类液相的拓扑结构强烈依赖于有序结构的类型。一个有限尺寸标度分析的熔融转变的c（2x2）相称的阶段表明，热关联长度指数nu和比热行为是一致的伊辛普适性类预期从分析参数。
We study the influence of thermal fluctuations in the phase diagram of a recently introduced two-dimensional phase field crystal model with an external pinning potential. The model provides a continuum description of pinned lattice systems allowing for both elastic deformations and topological defects. We introduce a nonconserved version of the model and determine the ground-state phase diagram as a function of lattice mismatch and strength of the pinning potential. Monte Carlo simulations are used to determine the phase diagram as a function of temperature near commensurate phases. The results show a rich phase diagram with commensurate, incommensurate, and liquidlike phases with a topology strongly dependent on the type of ordered structure. A finite-size scaling analysis of the melting transition for the c(2x2) commensurate phase shows that the thermal correlation length exponent nu and specific heat behavior are consistent with the Ising universality class as expected from analytical arguments.