INFLUENCE OF MN SUBSTITUTION ON THE MAGNETIC-PROPERTIES OF HO2FE14C COMPOUNDS

The crystallographic and magnetic properties of the compounds Ho 2Fe14-xMnxC have been investigated by means of x-ray diffraction and magnetic measurements. Magnetization measurements made in fields up to 38 T showed that the saturation moment exhibits a minimum at a Mn concentration corresponding to about x=2. The occurrence of this minimum is explained by antiparallel coupling between the Ho and 3d sublattice magnetization, the latter becoming strongly reduced with increasing Mn concentration. Most of the Ho2Fe14-xMnxC compounds investigated have a break in the magnetization curves measured at 4.2 K. This break is interpreted as the onset of decoupling between the antiparallel coupling between the rare-earth and 3d sublattice. A mean-field analysis was used to derive the intersublattice molecular-field coefficients nRT.