Elastic and electronic properties of hexagonal rhenium sub-nitrides Re3N and Re2N in comparison with hcp-Re and wurtzite-like rhenium mononitride ReN

Very recently, two hexagonal rhenium sub-nitrides Re3N and Re2N, which belong to a rather rare group of known metal-rich (M/N > 1) nitrides of heavy 4d, 5d metals, have been successfully synthesized, and their potential technological applications as ultra-incompressible materials have been proposed. In this work, we present a detailed ab initio study of recently synthesized rhenium sub-nitrides in comparison with hcp-Re and wurtzite-like rhenium mono-nitride ReN, with the purpose to evaluate the trends of the elastic, electronic properties, and chemical bonding in the series of these hexagonal systems as a function of the Re/N stoichiometry: Re -> Re3N -> Re2N -> ReN. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim