Triaxial-Stress-Induced Homogeneous Hysteresis-Free First-Order Phase Transformations with Stable Intermediate Phases
Triaxial-Stress-Induced Homogeneous Hysteresis-Free First-Order Phase Transformations with Stable Intermediate Phases
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DOI：
10.1103/physrevlett.118.025701
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发表时间：
2017-01-11
影响因子：
8.6
通讯作者：
Xiong, Liming
中科院分区：
文献类型：
--
作者：
Levitas, Valery I.;Chen, Hao;Xiong, Liming
从热力学预测和分子动力学模拟之后，发现特殊的三轴压缩-拉伸状态，其中硅（Si）晶格不稳定的应力对于半导体Si I和金属Si II相之间的直接和反向相变（PT）是相同的。这导致了独特的均匀和无杂质的一阶PT，其中每个中间晶格沿着的转换路径是在中性热力学平衡，可以被逮捕和研究固定在一个方向上的应变。通过接近这些应力状态，传统的两相系统不断转变为均匀的中间相。零滞后和均匀变换是各种PT应用的最佳特性，可大幅降低损伤和能量耗散。
Starting with thermodynamic predictions and following with molecular dynamics simulations, special triaxial compression-tension states were found for which the stresses for the instability of the crystal lattice of silicon (Si) are the same for direct and reverse phase transformations (PTs) between semiconducting Si I and metallic Si II phases. This leads to unique homogeneous and hysteresis-free first-order PTs, for which each intermediate crystal lattice along the transformation path is in indifferent thermodynamic equilibrium and can be arrested and studied by fixing the strain in one direction. By approaching these stress states, a traditional two-phase system continuously transforms to homogenous intermediate phases. Zero hysteresis and homogeneous transformations are the optimal property for various PT applications, which drastically reduce damage and energy dissipation.