The structural stability of Mn3Sn Heusler compound under high pressure

Abstract Pressure engineering has attracted growing interest in the understanding of structural changes and structure-property relations of layered materials. In this study, we investigated the effect of pressure on the crystal structure of Mn 3 Sn. In-situ high-pressure x-ray diffraction experiments revealed that Mn 3 Sn maintained hexagonal lattice symmetry within the pressure range of ambient to 50.4 GPa. The ratio of lattice constants c/a is almost independent of the pressure and remains constant at 0.80, indicating a stable cell shape. Density functional theory calculations revealed the strong correlation between the crystal structure and the localization of d electrons. The Mn 3 Sn has been found in flat energy bands near the Fermi level, exhibiting a large density of states (DOS) primarily contributed by the d electrons. This large DOS near the Fermi level increases the energy barrier for a phase transition, making the transition from the hexagonal phase to the tetragonal phase challenging. Our results confirm the structural stability of Mn 3 Sn under high pressure, which is beneficial to the robustness of spintronic devices.