MOSSBAUER-EFFECT EVIDENCE OF SPIN REORIENTATION IN (ER1-XCEX)(2)FE14BINTERMETALLIC COMPOUNDS

Spin reorientation in (Er1-xCex)(2)Fe14B system, originating from comp etition between the magnetic anisotropies of the erbium and iron subla ttices, was observed by the Fe-57 Mossbauer spectroscopy below room te mperature. The spin transition temperature is lowered by non-magnetic dilution within the rare earth crystal sublattice, caused by substitut ion of cerium for erbium. There is evidence that the process proceeds not at a discrete temperature but in a wide temperature range. The dis crete values of the Fe-57 hyperfine interaction parameters, derived fr om Mossbauer absorption spectra, are consistent with localized interac tions of iron atoms with their nearest neighbours. It was found that s ubstitution of cerium for erbium slightly reduces hyperfine magnetic f ields at iron sites and it only has a minute influence on the values o f the isomer shifts and quadrupole interactions.