NONCOLLINEAR SPIRAL MAGNETIC ORDER IN ITINERANT-ELECTRON MAGNETS

We use the local spin-density functional approximation together with the ASW-method to solve the band-structure problem self-consistently for noncollinear, incommensurate spiral magnetic structures. These occur e.g. in gamma-Fe according to recent neutron-diffraction experiments by Tsunoda. Our calculated total energies identify possible spiral ground states for gamma-Fe and reveal certain band-structure features responsible. Another case treated is YMn2 which possesses an antiferromagnetic ground state modulated by a long-period spiral. Our calculations correctly identify the latter but predict an antiferromagnetic order that differs from that suggested by Ballou et al. to explain neutron-diffraction data.