Magnetic phase stability and spin-dependent transport in CeNi4 M (M=Sc, Ti, V, Cr, Mn, Fe, and Co): First-principles study

Using first-principles density functional calculations, the structural, magnetic, and spin-dependent transport properties of a set of intermetallic compounds CeNi4 M (M=Sc-Co) are investigated. All the compounds are considered to be in the orthorhombic phase, in which a transition metal atom M substitutes for one of the Ni atoms in the parent hexagonal CeNi5 structure. The optimized lattice constants are shown to be in good agreement with the corresponding experimental data. The volume of CeNi4 M turns out to decrease with changing the M component from Sc to Co. Our calculations reveal that the ferromagnetic state is energetically more favorable for the compounds with M=Sc, Mn, Fe, and Co, while for CeNi4 Cr, the structure is found to be antiferromagnetic. Except for CeNi4 Sc, the magnetism in these compounds originates mainly from M atoms. The ferromagnetic coupling is mediated through the indirect d-d and d-f exchange interactions. The spin-dependent transport calculations show that the spin polarization in the diffusive regime is significantly higher than that in the ballistic one for these intermetallic compounds.