First-principles study of the structural stability and electronic structures of TaN

Abstract

Using the plane-wave pseudopotential method within the generalized gradient approximation, we have studied the structural stability and electronic structures for several TaN phases. Our results show CoSn is the calculated ground-state structure of TaN among the five crystallographic structures that have been studied. The order of energetic stability of phase structures of TaN from low to high is: CsCl < ZnS-B3 < NaCl < WC < CoSn. The higher stability of TaN in the CoSn and WC structures is due to the formation of pseudogap around the Fermi level and the stronger hybridization between N-2p states and Ta-5d states. TaN in all structures studied has a metallic nature. The calculated bulk modulus indicates that TaN in the WC structure may be a less compressible material. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.