The effect of Si substitution on the magnetocaloric properties of Al_1.2-xSi_xFe₂B₂ intermetallic system

The AlFe₂B₂ material has drawn considerable attention recently due to its magnetocaloric properties near room temperature. Here, we have investigated the magnetic and magnetocaloric properties of a series of Si-doped Al_1.2-xSi_xFe₂B₂ (0 ≤ x ≤ 0.25) compounds by x-ray diffraction, scanning electron microscopy (SEM), and dc magnetization measurements. The samples were prepared by arc-melting followed by drop-casting and annealing. The x-ray diffraction patterns confirmed that all samples exhibited the single-phase Cmmm-type orthorhombic crystal structure. SEM micrographs confirmed the homogeneity of the samples. A second-order ferromagnetic phase transition was observed near room temperature for all samples. While the Curie temperature (Tc) was minutely effected due to Si doping, the magnetocaloric properties were significantly enhanced. A peak magnetic entropy change of 7.39 Jkg^-1K^-1 was observed in the doped samples for a field change of 50 kOe. The experimental results and related discussion will be presented in detail.