Magnetic Diffuse Scattering Measurements Using Polarised Neutrons

Two distinct polarised neutron techniques are applicable to the. study of magnetic diffuse scattering. The first, used for ferromagnetic alloys, employs a polarised incident beam without analysis of the outgoing polarisation. This method has been widely used, chiefly by the Oak Ridge group, to study moment disturbances in ferromagnetic binary transition metal alloys. The second technique involves polarisation analysis and has been used to study spin correlations in concentrated spin glass materials, and moment defects in antif err.omagne tic alloys. Measurements on antiferromagnetic y-Mn alloys show that the usual assumption of a collinear moment defect is not valid. The spin correlations in certain concentrated spin glass alloys are found to have an incommensurate modulation. This may result from the modification of the antiferromagnetic couplings by the atomic correlations in the alloys.