ATOMIC AND MAGNETIC-MOMENT DISTRIBUTIONS IN FE2MNSI

Polarized neutron diffuse scattering studies made above and below the re-ordering temperature T-R on an Fe2MnSi crystal have revealed a rand om atomic arrangement of Mn and Fe atoms. The magnetic disturbance pro duced by Mn atoms is confined to the substituted sites. There appears to be greater change in the moment difference between Mn and Fe atoms on the Mn predominant B site with change in concentration x(B) for T < T-R than for T > T-R. Above and below T-R, the moments of Mn and Fe a toms on the Fe predominant A, C sites are very similar.