Structural, electronic and magnetic properties of negative thermal expansion material Mn3Cu1-xSnxN

We have investigated the structural, electronic and magnetic properties of Mn3Cu1-xSnxN(x=0, 0.5) using first-principles density functional theory within the generalized gradient approximation (GGA) + U schemes. The crystal structure of the compounds is tetragonal crystal for x=0 while it is a cubic crystal for x=0.5. Our spin-polarized calculations give a metallic ground state for the x= 0, 0.5 in agreement with experiments. From the charge density and density of states(DOS), the coupling between Sn 5p with Mn 3d and spin geometrical frustration effect are the main reasons for magnetic transition in Mn3Cu1-xSnxN. (C) 2010 Elsevier B.V. All rights reserved.