MOSSBAUER STUDY OF THE FE-57 HYPERFINE INTERACTIONS IN ND(CO0.95FE0.05)5

The **5**7Fe hyperfine interactions in Nd(Co//0//. //9//5Fe//0//. //0//5)//5 have been measured at different temperatures between 4. 2 K and 340 K by Mossbauer spectroscopy. An analysis of the results shows that Fe atoms preferentially occupy the 3 g site of the CaCu//5-type structure. This property, already observed in similar compounds, is interpreted in terms of steric considerations. The thermal variations of the hyperfine fields exhibit discontinuities associated with the magnetization reorientation. As in other systems, these are attributed to a discontinuity of the orbital contribution to the Fe moment. It is deduced that the easy direction of magnetization for Fe moments on the different crystallographic sites is perpendicular to the c-axis of the hexagonal structure.