Distributions of the hyperfine interaction parameters in (Er1-xSmx)2Fe14B as seen by Mossbauer spectroscopy

The distributions of the hyperfine interaction parameters, caused by substitution of Sm for Er in the (Er1-xSmx)(2)Fe14B system, were studied by Mossbauer spectroscopy both at room and liquid nitrogen temperatures. It was proved that the random distribution of the rare earth atoms over their crystal sites and the additive contribution of the Sm atoms to the values of the hyperfine interaction parameters at the iron crystal sites lead to a linear dependence of the average values of the Fe-57 hyperfine magnetic field, isomer shift and quadrupole interaction on the Sm concentration in the present compounds. From these linear relations, the contributions Delta(H), Delta(IS) and Delta(QS) to the values of the hyperfine magnetic field, isomer shift and quadrupole interaction, caused by the presence of the Sm atom in the nearest neighbour shell of the Fe crystal sites, were derived. No distinct correlations were found between the Delta(H), Delta(IS) and Delta(QS) values and those of the nearest neighbours and/or their distances from the Fe crystal sites. (C) 2000 Elsevier Science S.A. All rights reserved.