Mössbauer spectroscopy on RE2Fe14BHx (RE-Y,Ce, Dy,Er) alloys

RE₂Fe₁₄B alloys and some of their hydrides have been studied through⁵⁷Fe and¹⁶¹Dy Mössbauer spectroscopy (MS). For both the paramagnetic and ordered phases a consistent and physically sound analysis of the⁵⁷Fe spectra is presented. Fe hyperfine fields and the local magnetic moments are obtained and compared with magnetic and structural data. A spin reorientation is observed for Er₂Fe₁₄B. A constant collinear structure down to 4.2 K was determined for the other samples. The¹⁶¹Dy spectra are interpreted for a pure ¦J_Z=15/2 > ground multiplet in Dy₂Fe₁₄B and its hydride. The B₂ crystal field parameters were estimated empirically for the Dy-alloy. Their values can account for the anisotropy in the compounds.