Moment variations in disordered Co-Mn alloys

The magnetic neutron scattering from Go-Mn alloys in the concentration rang e between long-range ferromagnetism and antiferromagnetism is analysed usin g a simple magnetic environment model for itinerant systems with just one m agnetic species. 30, 35 and 40 at% Mn alloys at 100 K are magnetically free and display Lorentzian peaks at antiferromagnetic reciprocal lattice point s. The magnetic environment model predicts Lorentzian peaks and the variati on of peak height and width is well modelled. The peak width is consistent with predominantly first neighbour antiferromagnetic exchange interactions and the peak height compares well with an estimate based on the moment and Neel temperature of face centred cubic manganese. (C) 2000 Elsevier Science B.V. All rights reserved.