MAGNETIC-PROPERTIES OF CRYSTALLINE AND AMORPHOUS GDFE2HX ALLOYS PREPARED BY HYDROGENATION

Magnetic properties of crystalline c-GdFe2H4.(3) and hydrogen-induced amorphous a-GdFe2H3.3 which were prepared by hydrogenation of crystall ine CdFe2, with the C15 structure were investigated by magnetization m easurements and Fe-57 Mossbauer spectroscopy. The hydrogenation decrea ses the magnetic ordering temperature. The Curie temperatures are 360 K in c-GdFe2H4.3 and 469 K in GdFe2H3.3, which are noncollinear ferrim agnets with the compensation temperatures of 202 and 45 K, respectivel y. The Mossbauer spectra of c-GdFe2H4.3 at 297, 77.3 and 4.2 K consist of a sharp quadrupole doublet and a broadened Zeeman sextet, which in dicates that a quarter of the Fe atoms do not carry an ordered magneti c moment even at 4.2 K. The spectra of a-GdFe2H3.3 show a broadened se xtet with a distribution of hyperfine fields. The maximum of the distr ibution probabilities is located at 365 kOe at 4.2 K, a value which is larger than that of alpha-Fe. (C) 1998 Elsevier Science S.A.