Structural stability and pressure-induced phase transitions inMgH2

P. Vajeeston, P. Ravindran, B. C. Hauback, H. Fjellvåg, A. Kjekshus, S. Furuseth, M. Hanfland
2006 Physical Review B  
The structural stability of MgH 2 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
more » ... oints as well as bulk modulii are found to be in good agreement with theoretically calculated data. The bonding nature of MgH 2 is analyzed with the help of charge-density, charge-transfer, electron-localization-function, and Mulliken-population analyses which clearly show that all polymorphs of MgH 2 are to be classified as ionic materials with Mg and H in nearly 2ϩ and 1− states, respectively.
doi:10.1103/physrevb.73.224102 fatcat:nd5vtm2hzfdfnjcyjkmez5krtq