Structural, electronic and magnetic properties of η-carbides M3W3C (M = Ti, V, Cr, Mn, Fe, Co, Ni)

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

“…The bulk modulus was calculated as B = ( С 11 + 2 С 12 )/3 and polycrystalline shear ( G ) and Young's ( Y ) moduli were estimated within the Voigt‐Reuss‐Hill approximation (see details in the study by Suetin and Medvedeva). These moduli show the parabolic dependences across the 3 d series with a maximum in the middle (M = Mn) and a minimum at the beginning and end of the 3 d series (Figure ).…”

“…The appearance of η‐carbides may affect the magnetic properties of various WC‐based composite coatings . Two nonequivalent positions of the magnetic metal M in the geometrically frustrated lattice of η‐carbides lead to competing exchange interactions and a variety of magnetic properties depending on the M‐type …”

“…A comprehensive analysis of elastic constants can provide conclusions about phase stability, hardness, brittleness or ductility, as well as establish their microscopic mechanisms. Until now, the theoretical studies of η‐carbides have been limited to ternary M 3 W 3 C and M 6 W 6 C (M = Fe, Co), which are shown to be stable . The recent ab initio calculations demonstrated that M 3 W 3 C are stable phases for all 3 d metals .…”

“…Until now, the theoretical studies of η‐carbides have been limited to ternary M 3 W 3 C and M 6 W 6 C (M = Fe, Co), which are shown to be stable . The recent ab initio calculations demonstrated that M 3 W 3 C are stable phases for all 3 d metals . Furthermore, the ternary M 3 W 3 C carbides of the late elements (M = Fe, Co, and Ni) were predicted to be more stable than any binary carbide MC, M 3 C, M 6 C, M 23 C 6 ; they should have high hardness and bulk moduli B ≈ (320–350) GPa.…”

“…[18,19] Two nonequivalent positions of the magnetic metal M in the geometrically frustrated lattice of η-carbides lead to competing exchange interactions and a variety of magnetic properties depending on the M-type. [20][21][22]28] The knowledge of the elastic properties of η-carbides is important for a better understanding of their mechanical behavior in terms of atomic-scale interactions. A comprehensive analysis of elastic constants can provide conclusions about phase stability, hardness, brittleness or ductility, as well as establish their microscopic mechanisms.…”