Electronic structure and magnetism of YFe11Ti

Abstract

Self-cosistent band calculations for YFe11Ti have been performed with LMTO-ASA method in the frame of local spin density functional formalism. The electronic total energy calculations predict that the system is most stable when the Ti atoms are located at the 8f sites, while experimental results suggest the 8i sites for the Ti atoms. On the other hand, the calculated equilibrium volume of the unit cell exhibits fair agreement with the measured value. It is also shown that the unit cell volume increases with the Ti concentration, X in YFe12−XTiX, with a rate ΔV/ΔX=10 (Å3/unit cell), and the magnetic moment decreases with X with a rate ΔM/ΔX=−4μB. The total magnetic moment of YFe11Ti (X=1) is given as about 21.7μB. With a inclusion of the spin–orbit interaction in the LMTO Hamiltonian, the orbital magnetism and the magnetocrystalline anisotropy were further examined. The orbital magnetic moment per Fe atom is about 0.06μB and the anisotropy energy is obtained as 97μRy/f.u. The value leads to about 12.1×106 erg/cc, which is about the half of the measured value, 23×106 erg/cc at 1.5 K.