In order to monitor the peculiar temperature dependence of the magnetization of the compounds
YCo4B and CeCo4B from an atomistic point of view, samples doped with 1%57Fe were studied by
M??ssbauer spectroscopy. From the two Co-sites present in this structure (2 c, 6 i), only the latter were
found to be equipped by Fe. In the case of the Y-compound, the change of direction of the easy axis of
magnetization could be confirmed. The broad maximum observed for the magnetization of the Cecompound
is not reflected by the57Fe hyperfine field. ?? 1994 J.C. Baltzer AG, Science Publishers.
