The magnetic entropy change in La_0.8Ce_0.2Fe _11.4Si_1.6B_x compounds prepared by copper-mold casting

The magnetocaloric effect (MCE) of La_0.8Ce_0.2Fe _11.4Si_1.6B_x (x=0.00.5) compounds, prepared by a copper-mold casting (CMC) method, has been investigated. Comparing with the conventional arc-melting (CAM) method, the relatively homogenous composition and microstructure were achieved in the precursor alloys prepared by the CMC method. As a result, the annealing time is dramatically shortened from several weeks for CAM alloys to 2 h for CMC alloys, suggesting that CMC method is a time-saving and energy-saving method for fabrication of MCE alloys. On the other hand, it is revealed that B addition gives rise to an enhancement of Curie temperature (T_C), a reduction of thermal lag and magnetic hysteresis and a broadening of working temperature span as well. Although the peak value of magnetic entropy change decreases with B content, various B-contained compounds hold close refrigerant capacities. Comprehensively considering magnetocaloric properties of the B-contained La_0.8Ce_0.2Fe _11.4Si_1.6B_x compounds, it can be concluded that the B-contained compounds prepared by CMC method are promising candidates of magnetocaloric materials in practical application.