【摘要】 采用熔炼法制备了Pr2Fe17-xAlx系列化合物。利用X射线衍射和MPMS XL-7型磁强计对样品相结构和磁熵变进行了研究。结果表明:Pr2Fe17-xAlx系化合物保持了Th2Zn17型菱方结构,其居里温度可通过成分微调达到室温附近;Pr2Fe17-xAlx系化合物在居里点附近发生的相变属于二级相变,并在较宽温区范围内保持了较大的磁熵变。该化合物在2.0 T外场下的最大磁熵变达到纯金属Gd的60%左右,且其化学性质稳定,制冷温区宽,价格低,是一类具有较大应用潜力的新型室温磁制冷工质材料。更多还原

【Abstract】 A series of Pr₂Fe₁7-xAl_x alloys were prepared by the arc melting.The structure and magnetic entropy changes in Pr₂Fe₁7-xAl_x compounds were investigated by X-ray diffractometer and MPMS XL-7 magnetometer.The experimental results show that the crystal structure of Pr₂Fe₁7-xAl_x compounds keeps in Th₂Zn₁7-type rhombohedral,and the Curie temperature of Pr₂Fe₁7-xAl_x alloys can be shifted to nearly room temperature by a composition adjustment.The phase transition near Curie temperature of the Pr₂Fe₁7-xAl_x compounds belongs to the second order one which conduces large magnetic entropy changes of the compounds in a comparatively wide range of temperature.The maximal magnetic entropy changes of Pr₂Fe₁7-xAl_x compounds are about 60% of the pure metal Gd in the external magnetic field of 2 T.Pr₂Fe₁7-xAl_x compounds are the potential working media for magnetic refrigeration with their stable chemical properties,wide temperature range for magnetic refrigeration and especially low price.更多还原