The Adiabatic Temperature Changes in the Vicinity of the First-Order Paramagnetic-Ferromagnetic Transition in the Ni-Mn-In-B Heusler Alloy

The magnetocaloric properties of Ni-Mn-In-B Heusler alloy have been studied using direct measurements of the adiabatic temperature change (ΔT_AD(T,H)) , and indirectly by magnetization (M(T,H)), differential scanning calorimetry, and specific heat (C_P(T,H)) measurements. The presence of a first-order ferromagnetic-paramagnetic transition has been detected for Ni₅₀Mn_34.8In_14.2B at 320 K. The magnetocaloric parameters, i.e., the magnetic entropy change, ΔS_M = (2.9-3.2) J/kgK, and the adiabatic temperature change, ΔT_AD = (1.3-1.52) K, have been evaluated for Δμ₀H = 1.8 T from C_P(T,H) and M(T,H), and from C_P(T,H) and direct ΔT_AD(T,H) measurements, respectively, in the vicinity of the first-order transition temperature. The extracted magnetocaloric parameters are comparable to that of Gd.