Magnetocaloric properties and critical behavior of magnetic phase transition in La(Fe0.94−xNixCo0.06)11.4Si1.6B0.25 alloys

•The industrial grade purity alloy exhibits RT magnetocaloric effect.•Ni doping broadens temperature span of magnetic entropy change around RT.•MAP provides a novel method for determining magnetic phase transition. For the widespread application of solid magnetic refrigeration technology, this is one of the key technologies to realize the wide temperature range of magnetic entropy change near room temperature. In this paper, the effect of Ni-doping on the magnetocaloric properties and the temperature range of magnetic entropy change was studied for La(Fe0.94−xNixCo0.06)11.4Si1.6B0.25 alloy subjected to the industrial high-frequency suspension furnace. The results show that the Curie temperature of the alloy system can be adjusted to room temperature by changing the Ni content, and the temperature range of magnetic entropy change can be expanded effectively. In addition, the critical behavior of the industrial grade purity alloy system was evaluated by modified Arrott-plot and critical isotherm analysis methods, and the optimal values of critical parameters were obtained, providing a novel thermodynamic method to determine the critical behavior of magnetic phase transition in La(FeSi)13 alloy system.