Hydrogenation effects in R2Fe14Si2 (R = Y, Nd, Dy and Er) offstoichiometric compounds

Samples of R2Fe14Si2 (R = Y, Nd, Dy and Er) solid solutions were prepared by arc melting and exposed to hydrogenation. Characterization of hydrogenation effects was done using X-ray diffraction (XRD) and Mِssbauer spectroscopy. Rietveld refining of the XRD spectra showed that both lattice parameters a and c increased after hydrogenation, with the exception of Er2Fe14Si2, for which they decreased slightly. The values of the magnetic hyperfine fields corresponding to the four inequivalent lattice sites were found to increase after hydrogenation in all offstoichiometric compounds investigated. Changes in the relative site occupancies were observed. Our study is the first to evidence hydrogenation effects on the hyperfine magnetic fields in intermetallics.