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

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.