High-pressure phases of MgSiN2 from first-principles calculations
High-pressure phases of MgSiN2 from first-principles calculations
复制标题
第一性原理计算得出的 MgSiN2 高压相
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
G. de With
中科院分区：
文献类型：
--
作者：
C. Fang;H. Hintzen;G. de With
在局域密度近似下，采用密度泛函近似方法模拟了MgSiN 2的结构与压强之间的关系。在约16.5GPa的压力下，具有正交结构的MgSiN 2的低压（LP-）相转变为具有CsICl 2型结构的高压（HP-）改性。其中Mg和Si都被N八面体配位的HP-MgSiN 2具有约238 GPa的体积模量，远高于具有四面体配位的金属原子的LP改性的体积模量（约182 GPa）。HP-MgSiN 2是一种宽禁带半导体，其间接能隙约为4.3 eV，与LP-MgSiN 2类似。在Γ处的直接带隙约为5.8eV。
The relationship between structure and pressure for MgSiN2 has been simulated using a density functional approximation within the local density approximation. The low-pressure (LP-) phase of MgSiN2 with an orthorhombic structure transforms to a high-pressure (HP-) modification with a CsICl2-type structure at a pressure of about 16.5 GPa. HP-MgSiN2 , in which both Mg and Si are octahedrally coordinated by N, has a bulk modulus of about 238 GPa, much higher than that of the LP-modification (about 182 GPa) with tetrahedrally coordinated metal atoms. HP-MgSiN2 is a wide-gap semiconductor with an indirect energy gap of about 4.3 eV, similar to that of LP-MgSiN2. The direct gap at Γ is about 5.8 eV.