Ground-state electronic structure calculations of the multiple spin-density-wave state in γ-Fe

Abstract

The electronic structure calculations of a noncollinear multiple spin-density-wave (MSDW) state in \ensuremath{\gamma}-Fe, which was found in a recent molecular-dynamics calculation, have been performed on the basis of the first-principles tight-binding linear muffin-tin orbital method and the generalized gradient approximation potential. The calculated MSDW state is shown to be dominated by 3 Q waves with wave number $Q=0.6$ in units of $2\ensuremath{\pi}/a, a$ being the fcc lattice constant. The secondary waves are created so as to suppress the amplitude fluctuations of local magnetic moments. It is found that the energy of the MSDW state is lower than that of the single-Q helical state with $Q=0.6$ at any volume due to the dip of the density of states at the Fermi level. From the energy comparison of various magnetic structures, it is concluded that the MSDW state may be stabilized in the region $6.8<a<7.0$ a.u., while the MSDW state characterized by $Q=1.0$ seems to be stabilized below $a=6.8$ a.u.