In search of low-cost, hysteresis-free, broad working temperature magnetocaloric materials, Ni_2.24Mn_0.76Sn Heusler alloy has been prepared by the conventional arc melting method. The XRD pattern reveals that the sample is crystallized in Fm \(\overline{3}\) m space group in L2₁ cubic symmetry. The Maxwell's equation is employed on magnetic isotherms to determine the change in magnetic entropy. This alloy gives a reasonable magnetocaloric effect (\(\Delta S_{M}\) = 1.25 J/Kg-K and RCP = 83.87 J/Kg at 3 T) with a large working temperature (67 K at 3 T) near the room temperature. Critical exponents have been calculated using modified Arrott plot, Kouvel–Fisher plot, and critical isotherm analysis to understand the nature of phase transition and exchange interaction, causing magnetic ordering in the system. The values of critical exponents (β = 0.454 ± 0.015, γ = 1.145 ± 0.035, δ = 3.522 ± 0.009) and range of exchange interaction (σ = 1.698) fall in between long-range mean-field theory and short-range 3D Heisenberg model, indicating the complex nature of exchange interaction.

为了寻找低成本，无滞后，宽工作温度的磁热材料，已通过常规电弧熔化方法制备了Ni _2.24 Mn _0.76 Sn Heusler合金。XRD图案表明，样品在结晶FM \（\划线{3} \） 米空间群L2 ₁立方对称。麦克斯韦方程用于磁等温线，以确定磁熵的变化。该合金具有合理的磁热效应（\（\ Delta S_ {M} \） = 1.25 J / Kg-K，RCP = 3. T时为83.87 J / Kg，在室温附近有较大的工作温度（3 T时为67 K）。临界指数已使用修正的Arrott图，Kouvel–Fisher图和临界等温线分析进行了计算，以了解相变和交换相互作用的性质，从而引起系统中的磁序。临界指数（β  = 0.454±0.015 ，γ  = 1.145±0.035 ，δ  = 3.522±0.009）的值和交换相互作用的范围（σ  = 1.698）介于远程平均场理论和短程3D海森堡之间模型，表明交换交互的复杂性。