GD-155 MOSSBAUER EFFECTS STUDIES AND MAGNETIC-PROPERTIES OF GDFE11TI AND GDFE11TIH1-DELTA

Structural and magnetic properties of GdFe11Ti were studied and the co rresponding hydride of the composition GdFe11TiH1 - delta was prepared by solid gas reaction of the GdFe11Ti with hydrogen gas. The lattice constants as well as the saturation magnetization and Curie temperatur e have been determined and compared for both compounds. Gd-155 Mossbau er spectroscopy experiments have been performed on these materials. An analysis of the effect of hydrogen on the hyperfine parameters of GdF e11Ti has been undertaken. In contrast to carbon or nitrogen insertion , hydrogen is found to increase the electric field gradient at the Gd nuclei. The results are discussed and compared to the effects of H, C or N insertions in the R2Fe17 structure (R is a rare-earth element). M odification of the isomer shift is observed upon hydrogenation and ana lyzed in terms of electronic charge transfer from the Gd 6s orbitals o nto the H atoms. (C) 1998 Elsevier Science B.V. All rights reserved.