Effect of X-Ray Irradiation on Magnetocaloric Material, (MnNiSi)_1-xFe₂Ge_x

Magnetic refrigeration based on magnetocaloric effect (MCE) at room temperature is generally considered as a potential substitution for classical vapor compression systems due to its high efficiency and environmental friendliness. (MnNiSi)_1−x(Fe₂Ge)_x composition (x=0.34) alloy was prepared by arc melting, crushed, and sieved to approximately <32 microns. They were utilized in examining the possible magnetic and structural changes when exposed to a dosage of a continuous sweeping rate of ~>120 Gy/min and an absorbed dose of 35 kGy of X-ray radiation. This study reports observable trends in magnetic measurements. Magnetization in the magnetization vs. temperature (both heating and cooling) measurements showed an increase from 2.72 emu/g to 4.01 emu/g in the irradiated sample. The magnetization vs. magnetic field loops exhibited irradiation-induced magnetic hysteresis. The irradiated sample also exhibited an observable change in its coercivity of ΔH_c = 14.7% at 200 K. A maximum entropy change ΔS_mag of ~ 11.139 J/kg*K and a T_ave peak of 317.5 K was achieved for the pristine sample in comparison to ΔS_mag of ~ 11.349 J/kg*K and a T_ave peak of 312.5 K for the irradiated sample. These presented results provided deeper insights into tuning the magnetic and structural effects of irradiation in the (MnNiSi)_1−x(Fe₂Ge)_x composition (x=0.34) that can be utilized in a wide range of magnetocaloric applications in high-energy radiation environments.