B. Swinnen, J. Dekoster, J. Meersschaut, S. Demuynck, S. Cottenier, M. Rots Journal of Magnetism and Magnetic Materials 156 (1-3), 71-721996A1Published while none of the authors were employed at the CMMDOI http://dx.doi.org/10.1016/0304-8853(95)00791-1