Magnetic properties and magnetocaloric effects of Tm_1-x Er_x CuAl (x = 0.25, 0.5, and 0.75) compounds

We investigate the structural, magnetic, and magnetocaloric effects (MCE) of Tm_1−x Er_x CuAl (x = 0.25, 0.5, and 0.75) compounds. The compounds undergo a second-order phase transition originating from the ferromagnetic to paramagnetic transition around 3.2 K, 5 K, and 6 K, respectively. The maximum magnetic entropy changes ( − Δ S M max ) of Tm_1−x Er_x CuAl (x = 0.25, 0.5, and 0.75) are 17.1 J⋅kg⁻¹⋅K⁻¹, 18.1 J⋅kg⁻¹⋅K⁻¹, and 17.5 J⋅kg⁻¹⋅K⁻¹ under the magnetic field in the range of 0-2 T, with the corresponding refrigerant capacity (RC) values of 131 J⋅kg⁻¹, 136 J⋅kg⁻¹, and 126 J⋅kg⁻¹, respectively. The increase of − Δ S M max for Tm_0.5Er_0.5CuAl may be relevant to the change of magnetic moment distribution of Er and stress coming from element substitution. This work provides several compounds that can enrich the family of giant MCE materials in the cryogenic region.