Average Magnetic Moment of Mn Atoms in an Fe₉₀Mn₅Cr₅ Ternary Alloy

Abstract

Average magnetic moment of Mn in bcc Fe₉₀Mn₅Cr₅ alloy has been studied by means of polarized neutron diffuse scattering in order to investigate the anomalous magnetic behavior of Mu impurity in Fe. By assuming the average magnetic moment of Fe and Cr to have the same value as in an Fe₉₅Cr₅ alloy, we have determined the average magnetic moment of Mn at temperatures of 10 K, 150 K, 295 K and 383 K. The value of Mn average magnetic moments obtained for this alloy is larger than that in an Fe₉₅Mn₅ alloy at all temperatures. A simple nearest neighbor model has been discussed in which Mn atoms in Fe have either positive or negative moments according to the various environmental conditions. In Fe(Mu, Cr) alloys, the negative Mn moments will always flip to positive direction if it has at least one Cr atom in its nearest neighboring shell. This model has explained the experimental results at least qualitatively.