Influence of substitutions and hydrogenation on the structural and magnetic properties of (R’R’’)2Fe17 (R’, R’’ = Sm, Er, Ho): Compositions with promising fundamental characteristics

•Hydrogenation effect on structure and magnetism of R2Fe17-type compounds is studied.•Structural changes in alloys are accessed by XRD.•High-field magnetization study at low temperatures provide data on exchange parameter.•Features of change in hydrogen capacity with a change in the composition are revealed. The structural and magnetic properties of the (R,R’)2Fe17-type (R and R’ are heavy (Ho, Er) and light (Sm) rare earth metals, respectively) compounds and the (R,R’)2Fe17Hy hydrides are reported. The hydrides with a high hydrogen concentration (y ≥ 4) are obtained by direct hydrogen absorption by the intermetallics. The rhombohedral Th2Zn17-type of structure is inherent in the Sm containing parent compounds and hydrides. The unit cell increase and increased Curie temperature are characteristic of the hydrides. Magnetic properties of the samples are investigated in pulsed magnetic fields up to 60 T. Strong magnetic fields induce phase transitions in the compounds with a high content of heavy rare earth elements. The parameter of the intersublattice exchange interaction is estimated.