Revealing strong polytypism tendency in MgTe from first-principles

Abstract

The search for stable polytype phases of III-V and II-VI materials has attracted great interest in recent years due to their great potential for a broad range of applications. Here using density functional theory, we systematically explore electronic structure properties of cubic (3C) and hexagonal (2H, 4H and 6H) polytypes of magnesium telluride: MgTe. Total energies and nearest-neighbor bilayer interaction energies evidence that MgTe shows a high propensity to polytypism. This finding is further supported by mechanical and phonon stabilities of all polytype phases of MgTe. Additionally, ground structural properties, energetic stability, mechanical properties, band structure energies, and dynamical properties are examined in relation with the stacking sequence of 3C, 2H, 4H, and 6H polytypes in the Mg-Te system.