In weakly and strongly bonded semiconductors, the knowledge of accurate linear thermal expansion coefficients and Grüneisen constants play crucial roles for attaining the basic understanding of lattice anharmonicity and appraising their use as thermal management materials in designing different electronic devices. By adopting a realistic rigid-ion-model (RIM), we have reported the results of a comprehensive study on the phonon dispersions and thermodynamical properties of weakly bonded III-V AlX (X = P, As, and Sb) pnictides at ambient (P = 0 GPa) and high pressure (P = 8 GPa). The results are compared/contrasted with the strongly bonded III-Ns (AlN, GaN, and InN) and other materials. Specifically, we have linked the simulated negative thermal expansion (NTE) coefficient in AlX to the weakness of bond-bending forces which caused large softening in for and to attain more negative values at low T. In III-Ns, however, there is only a weak sign of the TA phonon softening which results in no negative values of and Unlike earlier first-principles studies in AlX indicating small NTE, our comprehensive RIM simulations have exhibited large negative values of and for AlP, AlAs and AlSb. In both weakly and strongly bonded solids the room temperature results of specific heat , Debye temperature thermal expansion coefficient (T), and Grüneisen constant provided very good agreement with the experimental and recent first-principles response function calculations. We strongly feel that this understanding of basic traits in different tetrahedral materials will be beneficial for specific device applications.

中文翻译：

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Al磷族化合物的负热膨胀系数——系统的现实压力相关晶格动力学研究

在弱键合和强键合半导体中，准确的线性热膨胀系数和格吕奈森常数的知识对于获得对晶格非和谐性的基本理解以及评估它们在设计不同电子设备中作为热管理材料的使用起着至关重要的作用。通过采用现实的刚性离子模型（RIM），我们报告了对弱键合 III-V AlX（X = P、As 和 Sb）磷族化物在环境（ P = 0 GPa) 和高压 (P = 8 GPa)。结果与强键合 III-N（AlN、GaN 和 InN）及其他材料进行了比较/对比。具体来说，我们将 AlX 中模拟的负热膨胀 (NTE) 系数与键弯曲力的弱点联系起来，这导致了大的软化，并在低 T 下获得更多的负值。然而，在 III-N 中，只有TA 声子软化的微弱迹象，导致 和 没有负值。 与早期的 AlX 第一性原理研究表明 NTE 较小不同，我们的综合 RIM 模拟显示 AlP、AlAs 和 AlSb 的 和 为大负值。在弱键合固体和强键合固体中，比热、德拜温度热膨胀系数 (T) 和 Grüneisen 常数的室温结果与实验和最近的第一原理响应函数计算非常吻合。我们强烈认为，对不同四面体材料的基本特性的了解将有利于特定的设备应用。