Ground state, phonon spectrum, and superconducting properties of the cubic inverse perovskite Sc3AlN

Abstract

We present results of ab initio theoretical investigations of the structural, elastic, and electronic properties of the cubic inverse perovskite Sc3AlN by employing the plane-wave pseudopotential method within the generalized gradient approximation. The calculated ground-state parameters are in agreement with available experimental and previous theoretical results. In agreement with experimental studies, it has been found that the density of states at the Fermi level is governed by the Sc 3d electrons. A linear-response approach to density-functional theory is used to derive the phonon dispersion curves, vibrational density of states, and the electron-phonon coupling parameter. Our results show that the electron-phonon interaction in Sc3AlN is much weaker than the corresponding interaction in the isoelectronic intermetallic perovskite material MgCNi3 suggesting that the former is not likely to be a superconductor.