High-Field Magnetization Study of $R_{2}{\rm Fe}_{17}{\rm H}_{3}$ ($R={\rm Tb}$, Dy, Ho and Er) Single-Crystalline Hydrides

The high-field magnetization process in the hydrogen-charged R
₂
Fe
₁₇
H
₃
(R=Tb , Dy, Ho and Er) single crystals is studied along principal crystallographic directions at T=4.2 K and compared with that of the known parent R
₂
Fe
₁₇
compounds. Substantial changes of the magnetic anisotropy behavior induced by hydrogenation are found. Depending on the rare earth atom, the R
₂
Fe
₁₇
H
₃
compounds possess the “easy-axes”, “easy-cone” and “easy-plane” types of magnetocrystalline anisotropy (MCA), whereas the precursors R
₂
Fe
₁₇
have the easy-plane type of MCA only. The various observed types of the field-induced phase transitions in R
₂
Fe
₁₇
H
₃
are discussed and information on the effect of hydrogen on the strength of R-Fe coupling is obtained.