Structural stability and pressure-induced phase transitions in MgH 2
Structural stability and pressure-induced phase transitions in MgH 2
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DOI：
10.1103/physrevb.73.224102
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发表时间：
2006-06
影响因子：
3.7
通讯作者：
P. Vajeeston;P. Ravindran;B. Hauback;H. Fjellvåg;A. Kjekshus;S. Furuseth;M. Hanfland
中科院分区：
文献类型：
--
作者：
P. Vajeeston;P. Ravindran;B. Hauback;H. Fjellvåg;A. Kjekshus;S. Furuseth;M. Hanfland
用高压同步加速器X射线衍射法研究了氢化镁在16 Gpa以下的结构稳定性。在这个压力范围内已经发现了几个由压力引起的相变。由于变质剂和变质剂之间的结构相似，高压形式在压力释放后可以稳定为亚稳定相。实验观察到的结构转变顺序、转变点处的体积变化以及体弹性模量与理论计算值符合得很好。用电荷密度、电荷转移、电子局域函数和密立根布居分析等方法分析了氢化镁的成键性质。结果表明，氢化镁的所有晶型都属于离子材料，镁和氢分别以近2和1�态存在。
The structural stability of MgH2 has been studied up to 16 GPa using a high-pressure synchrotron x-ray diffraction technique. Several pressure-induced phase transitions have been identified in this pressure range. Owing to the close structural similarity between the and modifications the high-pressure form can be stabilized as a metastable phase after pressure release. The experimentally observed structural transition sequence and the volume changes at the transition points as well as bulk modulii are found to be in good agreement with theoretically calculated data. The bonding nature of MgH2 is analyzed with the help of charge-density, charge-transfer, electron-localization-function, and Mulliken-population analyses which clearly show that all polymorphs of MgH2 are to be classified as ionic materials with Mg and H in nearly 2 and 1� states, respectively.