摘要
The structural and magnetocaloric properties of Mnl.35Feo.65P1-xSix compounds are investigated. The Si- substituted compounds, Mn1.35Fe0.65Pl-xSix with x = 0.52, 0.54, 0.55, 0.56, and 0.57, are prepared by high-energy ball milling and the solid-state reaction. The X-ray diffraction shows that the compounds crystallize into the Fe2P-type hexagonal structure with space group P62m. The magnetic measurements show that the Curie temperature of the compound increases from 253 K for x = 0.52 to 296 K for x= 0.56. The isothermal magnetic-entropy change of the Mnl.35Fe0.65Pl-xSix compound decreases with the Si content increasing. The maximal value of the magnetic-entropy change is about 7.0 J/kg.K in the Mnl.35Feo.65Po.48Sio.52 compound with a field change of 1.5 T. The compound quenched in water possesses a larger magnetic entropy change and a smaller thermal hysteresis than the non-quenched samples. The thermal hysteresis of the compound is less than 3.5 K. The maximum adiabatic temperature change is about 1.4 K in the Mnl.35Fe0.65P0.45Si0.55 compound with a field change of 1.48 T.
The structural and magnetocaloric properties of Mnl.35Feo.65P1-xSix compounds are investigated. The Si- substituted compounds, Mn1.35Fe0.65Pl-xSix with x = 0.52, 0.54, 0.55, 0.56, and 0.57, are prepared by high-energy ball milling and the solid-state reaction. The X-ray diffraction shows that the compounds crystallize into the Fe2P-type hexagonal structure with space group P62m. The magnetic measurements show that the Curie temperature of the compound increases from 253 K for x = 0.52 to 296 K for x= 0.56. The isothermal magnetic-entropy change of the Mnl.35Fe0.65Pl-xSix compound decreases with the Si content increasing. The maximal value of the magnetic-entropy change is about 7.0 J/kg.K in the Mnl.35Feo.65Po.48Sio.52 compound with a field change of 1.5 T. The compound quenched in water possesses a larger magnetic entropy change and a smaller thermal hysteresis than the non-quenched samples. The thermal hysteresis of the compound is less than 3.5 K. The maximum adiabatic temperature change is about 1.4 K in the Mnl.35Fe0.65P0.45Si0.55 compound with a field change of 1.48 T.
基金
Project supported by the National Natural Science Foundation of China （Grant No. 50961010） and the Natural Science Foundation of Inner Mongolia, China （Grant No. 20080404Zd01）.
