Theoretical Predictions for High-Pressure Elastic, Mechanical, and Phonon Properties of SiGe Alloy

Elastic, mechanical, and phonon properties of zinc blende (ZB)-type SiGe ordered alloy were theoretically investigated in detail under pressures up to 12 GPa. Unlike earlier theoretical calculations of literature, a Stillinger-Weber-type interatomic potential was applied to this work for the first time with geometry optimization calculations. Pressure dependence of typical cubic elastic constants, bulk, shear and Young moduli, elastic wave velocities, Kleinman parameter, elastic anisotropy factor, phonon dispersion, as well as density of states of SiGe alloy were calculated and compared with other results when available. In general, our results for the above considered quantities of SiGe alloy are satisfactory and compare well the former theoretical data of alloy.