摘要
FesoMn15-xCoxNi35 （x=0, 1, 3, 5, 7） alloys were prepared by arc melting under purified argon atmosphere. The ingots were homogenized at 930℃ for 90 h followed by water quenching. The crystal structure, magnetic properties and magnetocaloric effects of the alloys were studied by X-ray diffraction （XRD） and MPMS-7-type SQUID. The results show that all samples still maintained a single γ-（Fe, Ni）-type phase structure. With the increase of the content of Co, the Curie temperatures of these alloys increased and exhibited a second-order magnetic transition from ferromagnetic （FM） to paramagnetic （PM） state near Curie temperature. The maximum magnetic entropy change and the relative cooling power of Fe50Mn10CosNi35 alloy was 2.55 J/kg.K and 181 J/kg, respectively, for an external field change of 5 T. Compared with rare earth metal Gd, FesoMnls-xCoxNi35 series of alloys have obvious advantage in resource price; their Curie temperatures can be tuned to near room temperature, maintain a relatively large magnetic entropy change at the same time and they are a type of potential magnetic refrigeration materials near room temperature.
Fe50Mn15-xCoxNi35(x=0,1,3,5,7)alloys were prepared by arc melting under purified argon atmosphere.The ingots were homogenized at 930°C for 90h followed by water quenching.The crystal structure,magnetic properties and magnetocaloric effects of the alloys were studied by X-ray diffraction(XRD)and MPMS-7-type SQUID.The results show that all samples still maintained a single-(Fe,Ni)-type phase structure.With the increase of the content of Co,the Curie temperatures of these alloys increased and exhibited a second-order magnetic transition from ferromagnetic(FM)to paramagnetic(PM)state near Curie temperature.The maximum magnetic entropy change and the relative cooling power of Fe50Mn10Co5Ni35alloy was 2.55 J/kg·K and 181 J/kg,respectively,for an external field change of 5T.Compared with rare earth metal Gd,Fe50Mn15-xCoxNi35 series of alloys have obvious advantage in resource price;their Curie temperatures can be tuned to near room temperature,maintain a relatively large magnetic entropy change at the same time and they are a type of potential magnetic refrigeration materials near room temperature.
基金
supported by the National Natural Science Foundation of China(Grant Nos.11032011 and 10872202)
the Guangdong Provincial Science and Technology Program(Grant No.2010B050300008)
the Guangzhou Municipal Science and Technology Program(Grant No.12F582080022)
the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(Grant No.x2clB7120290)
the Fundamental Research Funds for the Central Universities(Grant Nos.2012ZZ0013 and 2014ZZ0005)
