Magnetic and Magnetocaloric Properties of Ho1 – xYx(Co0.84Fe0.16)2 Compounds

Crystal structure, temperature and field dependences of magnetization, high-field susceptibility, and magnetocaloric effect (MCE) of Ho 1 – x Y x (Co 0.84 Fe 0.16 ) 2 polycrystalline compounds ( x = 0–1) in magnetic fields up to 90 kOe in a temperature range of 5–400 K are investigated. An analysis of temperature dependences of magnetization (σ) showed that, depending on the yttrium content ( x ), up to three “critical” temperatures can be simultaneously present in the studied samples: spin-reorientation ( T sr ), magnetic compensation point ( T comp ), and Curie temperature ( T C ). The temperature dependence of the high-field susceptibility (χ hf ) of all samples with x < 1 has an extremum in the vicinity of 100 K, where a significant MCE is observed, associated with a sharp change in the magnetization of the rare-earth sublattice. The temperature dependences of the magnetic entropy change (Δ S m ) and the adiabatic temperature change (Δ T ad ) have a complex shape and reflect all the above-mentioned “critical” temperatures observed at different x .