The structural, electronic, magnetic and mechanical properties of quaternary Heusler alloys ZrTiCrZ (Z = Al, Ga, In, Si, Ge, Sn): a first-principles study. (25th May 2016) - Yan, Peng-Li
Abstract: The structural, electronic, magnetic and mechanical properties of the quaternary Heusler alloys ZrTiCr Z ( Z = Al, Ga, In, Si, Ge, Sn) have been investigated firstly by using the first-principles calculations. The preferred configurations of the ZrTiCr Z alloys are all Y -type (I). At their equilibrium lattice constants, the ZrTiCr Z alloys are half-metallic (HM) ferrimagnets for Z = Al, Ga and In, while spin-gapless semiconductor (SGS) antiferromagnets (AFM) for Z = Si, Ge and Sn. The total magnetic moments μ t of the ZrTiCr Z alloys are −1 μ B / f .u . for Z = Al, Ga and In, while 0 μ B / f .u . for Z = Si, Ge and Sn, both linearly scaled with the total number of valence electrons Z t by Slater–Pauling rule μ t = Z t − 18 . The elastic constants C 11, C 12 and C 44 of the single crystal and the related elastic moduli G, B, E, υ and A of the polycrystalline aggregates are also calculated and used to study the mechanical stability of these alloys. Although the Curie temperatures T C of the ZrTiCr Z alloys are overestimated by using the mean field approximation (MFA), they can be better estimated by including the exchange interactions. Finally, the HM stabilities as well as the total and atomic magnetic moments of the ZrTiCr Z alloys ( Z = Al, Ga, In) under either hydrostatic strain or tetragonal strain are also discussed.