论文标题
2D铁电在其副层转化的弹性
Elasticity of 2D ferroelectrics across their paraelectric phase transformation
论文作者
论文摘要
二维（2D）材料在二相变化中的机械行为尚不清楚，并且范式的SNSE单层弹性温度（$ t $）弹性 - 铁电2D材料将相邻型的转向型单位电池（U.C.）从矩形转向正方形 - 在此处介绍的是一种进步的方式。首先，它们的零$ -t $ {\ em弹性能量景观}让位于确定弹性行为的平均值（类似于Boltzmann）的平均值。这些估计值与应变 - 裂开方法的结果相辅相成，该方法采用了能量景观或{\ em ab instib}分子动力学（MD）数据。两种方法都捕获了弹性模量$ \ langle c_ {11}（t）\ rangle = \ langle c_ {22}（t）（t）\ rangle $，由于结构转换，弹性模量的合并。 The broad evolution and sudden changes of elastic parameters $\langle C_{11}(T)\rangle$, $\langle C_{22}(T)\rangle$, and $\langle C_{12}(T)\rangle$ of these atomically-thin phase-change membranes establishes a heretofore overlooked connection among 2D materials and soft matter.
The mechanical behavior of two-dimensional (2D) materials across 2D phase changes is unknown, and the finite temperature ($T$) elasticity of paradigmatic SnSe monolayers -- ferroelectric 2D materials turning paraelectric as their unit cell (u.c.) turns from a rectangle onto a square -- is described here in a progressive manner. To begin with, their zero$-T$ {\em elastic energy landscape} gives way to (Boltzmann-like) averages from which the elastic behavior is determined. These estimates are complemented with results from the strain-fluctuation method, which employs the energy landscape or {\em ab initio} molecular dynamics (MD) data. Both approaches capture the coalescence of elastic moduli $\langle C_{11}(T)\rangle=\langle C_{22}(T)\rangle$ due to the structural transformation. The broad evolution and sudden changes of elastic parameters $\langle C_{11}(T)\rangle$, $\langle C_{22}(T)\rangle$, and $\langle C_{12}(T)\rangle$ of these atomically-thin phase-change membranes establishes a heretofore overlooked connection among 2D materials and soft matter.
