Ab initio study of Sc3MO (M = Al, Ga, In, Tl) and systematics in Sc3MZ (Z = B, C, N, O)

Abstract

Ab initio theoretical investigation of Sc3MO (M = Al, Ga, In, Tl) system has been carried out. The band structure calculations were carried out by an augmented plane wave and local orbital (APW + LO) method based on density functional theory (DFT) using WIEN2k. Lattice parameters obtained by volume optimization for Sc3MO system do not increase monotonically as one goes down the group from Al to Tl but shows a minimum for M = Ga. The bulk modulus shows anti-correlation with the lattice parameter. Fermi energy EF lies roughly 1 eV above a pseudo gap and the non-zero Density of States (DOS) at EF, N(EF) ∼ 3.1 to 3.6 states/eV indicates metallicity. A comparison with Sc3MZ (Z = B, C, N and O) brings out systematics in this series of compounds.