Effects of magnetic field and hydrostatic pressure on the antiferromagnetic–ferromagnetic transition and magneto-functional properties in Hf1-xTaxFe2 alloys

In this study, the thermal expansion of Hf1-xTaxFe2 (x = 0.10, 0.13, 0.15) compounds by adjusting the Ta concentration was successfully regulated. The magnetocaloric properties, hydrostatic pressure affecting the antiferromagnetic–ferromagnetic transition, and magnetostriction in the low magnetic field were studied. The ΔSM values of 3.3 J·(kg·K)−1 and 3.6 J·(kg·K)−1 were obtained under magnetic fields of 10 kOe and 15 kOe in the Hf0.85Ta0.15Fe2, respectively. In the antiferromagnetic–ferromagnetic state transformation process under hydrostatic pressure up to 0.8 GPa, the state temperature does not decrease in a strictly linear manner. Outstanding magnetostrictive properties of 0.12% were obtained at a magnetic field of 10 kOe. This kind of alloy is supposed to be controlled under hydrostatic pressure to obtain good magnetic refrigeration performance and magnetostrictive properties.