First‐Principles Study of Structure, Magnetic Properties, and Stability of η‐Carbides (M,Fe)₃W₃C (M = Ti, V, Cr, Mn, Co, and Ni)

Abstract

The elastic moduli, stability, electronic structure, and magnetic properties of quaternary η‐carbides M3−xFexW3C (M = Ti, V, Cr, Mn, Fe, Co, Ni and x = 0,1,2) are studied using ab initio calculations. Stabilities of quaternary M3−xFexW3C and binary carbides (MC, M3C, M6C, M7C3, M5C2, M23C6) are compared and their competition depending on the type of metal is discussed. The η‐phases are the only stable carbides for the late transition metals (Fe, Co, and Ni), whereas they are least stable for the beginning 3d‐elements (M = Ti, V). The magnetic properties of η‐carbides are shown to depend strongly on the type and concentration of the 3d metal M.