Hydrogenation, Disproportionate, Desorption, and Recombination in the Sm₂Co_17–xFe_x–H₂ System (JC = 3.9 and 5.95). X-Ray Diffraction.

Abstract

Differential thermal analysis and X-ray diffraction are used to study phase transitions in the Sm₂Co_17–xFe_x–H₂ system (x = 3.9 and 5.95) during conventional solid HDDR at 0.57–4.0 MPa hydrogen pressure and temperature up to 950 °C. The ferromagnetic phase with Th₂Zn₁₇ structure disproportionates after interaction with hydrogen for 1 h at 1.1 and 0.6 MPa with x = 3.9 and 5.95, respectively, at 700 °С into SmH_2±x, cobalt, and intermetallic FeCo. Recombination in vacuum at 770–950 °C leads to a two-phase alloy consisting of the Th₂Zn₁₇-type phase and intermetallic FeCo.