Search for new half-metallic ferromagnets in semi-Heusler alloys NiCrM (M = P, As, Sb, S, Se and Te)

Abstract

The first-principles calculation within density-functional theory is used to search for new candidates of half-metallic ferromagnets in semi-Heusler alloys NiCrM (M = P, As, Sb, S, Se and Te). Our calculations predict that NiCrP, NiCrSe and NiCrTe are half-metallic ferromagnets (HMFs) with magnetic moments of nearly 3 or 4 µ B /fu and HM gaps of 0.263, 0.047 and 0.102 eV, respectively. Other compounds are so-called nearly HMFs. Substitution of the sp atoms cannot be responsible for the formation of the band gap, but results in a shift in the Fermi level and the loss of half-metallicity. The half-metallicity of NiCrP and NiCrTe can be retained when the lattice parameter is changed by about 2%-3%.

Above-room-temperature ferromagnetism in half-metallic Heusler compounds NiCrP, NiCrSe, NiCrTe, and NiVAs: A first-principles study

“…The purpose of the present work is a first-principles study of the exchange interactions and the temperature of magnetic phase transition for four semi Heusler compounds NiCrZ (Z=P, Se, Te) and NiVAs that were recently predicted to be half-metals [23,24]. For all four systems we find the Curie temperature substantially exceeding room temperature.…”

“…For each compound we performed calculations for two values of the lattice parameter: the theoretical equilibrium parameter [23,24] and the lattice parameter of a binary semiconductor (Table I) that can be considered as a possible substrate for growing the corresponding Heusler alloy: GaAs for NiCrP and NiCrSe and InP for NiVAs and NiCrTe. The radii of all atomic spheres are chosen equal.…”

“…Our DOS are in good agreement with the DOS presented in Refs. [23,24]. In Table I, the calculated magnetic moments are collected.…”

“…Galanakis studied the appearance of half-metallic ferromagnetism in quaternary Heusler alloys [22]. Xing et al have predicted the half-metallic ferromagnetism in NiCrZ (Z=P, Se, Te) and NiVAs semi Heusler compounds [23,24].…”

Ab initio electronic and magnetic properties of half-metallic NiCrSi and NiMnSi Heusler alloys: The role of defects and interfaces

“…Finally, the effect of stress on the magnetic anisotropy of thin NiMnSb films and the role of defects have been explored. 63,64 Based on the success of first-principles electronic structure calculations to describe the properties of NiMnSb, several authors have predicted new half-metallic Heusler alloys crystallizing in the C1 b structure of semi-Heusler compounds like NiCrM and NiVM (M= P, As, Sb, S, Se and Te), 65,66,67 and XCrAl (X= Fe, Co, Ni) and NiCrZ (Z= Al, Ga, In). 68 Recently, Katayama-Yoshida and collaborators published a paper including also ab-initio calculations on NiMnSi semi-Heusler alloy, which was predicted to have a Curie temperature of 1050 K, 69 exceeding even the 730 K shown by NiMnSb.…”