Pressure-induced B1-B2 phase transition in alkali halides: General aspects from first-principles calculations.
Pressure-induced B1-B2 phase transition in alkali halides: General aspects from first-principles calculations.
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DOI：
10.1103/physrevb.49.3066
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发表时间：
1994-02
期刊：
影响因子：
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通讯作者：
A. M. Pendás;V. Luaña;J. Recio;M. Flórez;E. Francisco;M. Blanco;L. Kantorovich
中科院分区：
文献类型：
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作者：
A. M. Pendás;V. Luaña;J. Recio;M. Flórez;E. Francisco;M. Blanco;L. Kantorovich
本文介绍了碱卤化物中B1-B2相变的基本原理、热力学和动力学方面的一般研究。特别注意的是(a)如何构建与一般量子化学技术一起使用的日益复杂的模型，以及(b)所分析的能量和吉布斯势面的拓扑和对称性相关特征。我们的结果表明，这种转变可以被认为是在晶格参数收缩的同时，在原始的B1晶胞中同时打开了菱面角。跃迁路径在很大程度上依赖于压力，并表现出巨大且不对称的吉布斯势垒，这些势垒定性地解释了围绕滞后现象的许多经验事实。
A first principles, general study of the thermodynamic and kinetic aspects of the B1-B2 phase transition in alkali halides is presented. Particular attention is paid to (a) how to construct models of increasing complexity to be used with generic quantum-chemistry techniques and (b) the topological and symmetry-dependent features of the energetic and the Gibbs potential surfaces analyzed. Our results indicate that the transition may be thought of as involving the simultaneous opening of the rhombohedral angle in the primitive B1 crystallographic cell while a contraction of the lattice parameter takes place. Transition paths depend strongly on pressure and show large and asymmetric Gibbs barriers that qualitatively account for many of the empirical facts around the phenomenon of hysteresis.