Magnetic Properties of the Hydrides of Selected Rare‐Earth Intermetallic Compounds with Transition Metals

Abstract

ErFe 2 , TmFe 2 and HoFe 2 have been found to form stable hydrides of composition ErFe 2 H 3.9 , TmFe 2 H 4.3 , and HoFe 2 H 4.47 , when exposed to hydrogen at 3.6 × 10 6 Pa at room temperature. X‐ray diffraction reveals an expansion of the ErFe 2 lattice parameter from 7.282 ± 0.001 to 7.828 ± 0.001 Å , the expansion of the TmFe 2 lattice parameter from 7.238 ± 0.001 to 7.839 ± 0.001 Å , and the expansion of the HoFe 2 lattice parameter from 7.284 ± 0.001 to 7.880 ± 0.001 Å with hydrogen absorption. Magnetization measurements as a function of temperature and field were made on these hydrides. The compensation temperature observed at 480 K for ErFe 2 and 233 K for TmFe 2 was shifted to 42 K and 8 K, respectively, upon hydriding. Magnetic moments measured at 4.2 K in an applied field of 120 kOe are 6.45 and 5.60 μB/FU for TmFe 2 and HoFe 2 , respectively. These large moments arise due to the reduction of the iron moment. Results on hydrides of NdCo 5 and DyCo 5.2 are also presented.