Magnetic excitations in metallic antiferromagnets Fe0.5Mn0.5 and Fe0.7Mn0.3

Abstract

Magnetic excitations in the metallic antiferromagnet Fe0.5Mn0.5 were investigated using the inelastic neutron scattering technique at low temperatures well below the antiferromagnetic transition temperatures (TN). The observed peak positions in low energies well sit on the antiferromagnetic dispersion relation reported in the early study. However, the peak positions in higher energies shift to higher energies than that of the antiferromagnetic spin wave dispersion relation. This behavior is the same as one of the behaviors suggesting that the spin waves merge with the continuum of the individual particle-hole excitations at higher energies in Fe0.7Mn0.3.