Groupe d'Etudes de la Matière Condensée, CNRS-Université de Versailles, 45 Avenue des Etats Unis, F-78035 Versailles Cedex, France.
J Chem Phys. 2013 Nov 21;139(19):194706. doi: 10.1063/1.4829462.
The present work is devoted to the spatio-temporal investigations of spin-crossover lattices during their thermal relaxation from high- to low-spin state. The analysis is performed using Monte Carlo simulations on a distortable 2D lattice the sites of which are occupied by high-spin (HS) or low-spin (LS) atoms. The lattice is circular in shape and the HS to LS transformation results in single domain nucleation followed by growth and propagation processes. The evolution of the LS:HS interface is monitored during the relaxation process, through the mapping of spin states, displacement fields, local stresses, and elastic energy. The results show a curved interface, the curvature of which is reversed at the mid-transformation. The local stresses and elastic energy peak at the vicinity of the HS:LS interface, with sizeable dependence upon the position along the front line which evidences the edge effects.
本工作致力于研究自旋交叉晶格在从高自旋态到低自旋态的热弛豫过程中的时空变化。采用蒙特卡罗模拟方法，在一个可变形的二维晶格上进行了分析，该晶格的位置由高自旋（HS）或低自旋（LS）原子占据。晶格为圆形，HS 到 LS 的转变导致单畴成核，随后是生长和扩展过程。通过自旋态、位移场、局部应力和弹性能量的映射，在弛豫过程中监测 LS:HS 界面的演化。结果表明，界面是弯曲的，在相变过程中曲率发生反转。局部应力和弹性能量在 HS:LS 界面附近达到峰值，并且与沿前线的位置有很大的依赖性，这证明了边缘效应的存在。
