Magnetic entropy change (𝛥 𝑆M); adiabatic temperature change (𝛥 𝑇ad); heat treatment; microstructure.
The magnetocaloric effect of Gd5Si2Ge2 alloys under heat treatment conditions are investigated in low magnetic fields. The magnetocaloric effect (MCE) is studied by measuring magnetic entropy change (𝛥 𝑆M) and adiabatic temperature change (𝛥 𝑇ad) in a magnetic field of 1.5 T using a vibrating sample magnetometer (VSM) and a home-made magnetocaloric effect measuring apparatus, respectively. The maximum 𝛥 𝑆M of the alloys increases by 200% from 4.38 to 13.32 J kg-1 K-1, the maximum 𝛥 𝑇ad increases by 105% from 1.9 to 3.9 K when compared to the as-cast due to the homogeneous composition distribution and microstructure, while the magnetic ordering temperature is slightly reduced. These results indicate that the annealed Gd5Si2Ge2 compounds are promising as high-performance magnetic refrigerants working room temperature in relatively low magnetic fields.
Volume 42 | Issue 1