An investigation on the magnetostructural transformation and magnetocaloric properties of Ni48-xCo2Mn38＋xSn12（x = 0, 1.0, 1.5, 2.0, and 2.5） ferromagnetic shape memory alloys is carried out. With the partial replac...An investigation on the magnetostructural transformation and magnetocaloric properties of Ni48-xCo2Mn38＋xSn12（x = 0, 1.0, 1.5, 2.0, and 2.5） ferromagnetic shape memory alloys is carried out. With the partial replacement of Ni by Mn in the Ni_（48）Co2Mn38Sn12 alloy, the electron concentration decreases. As a result, the martensitic transformation temperature is decreased into the temperature window between the Curie-temperatures of austenite and martensite. Thus, the samples with x = 1.5 and 2.0 exhibit the magnetostructural transformation between the weak-magnetization martensite and ferromagnetic austenite at room temperature. The structural transformation can be induced not only by the temperature,but also by the magnetic field. Accompanied by the magnetic-field-induced magnetostructural transformation, a considerable magnetocaloric effect is observed. With the increase of x, the maximum entropy change decreases, but the effective magnetic cooling capacity increases.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51601092,51571121,and 11604148)the Fundamental Research Funds for the Central Universities,China(Grant Nos.30916011344 and 30916011345)+5 种基金Jiangsu Natural Science Foundation for Distinguished Young Scholars,China(Grant No.BK20140035)China Postdoctoral Science Foundation(Grant No.2016M591851)the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20160833 and BK20160829)Qing Lan Project of Jiangsu Province,ChinaPriority Academic Program Development of Jiangsu Higher Education Institutions,ChinaNMG–NJUST Joint Scholarship Program for Ishfaq Ahmad Shah(Student ID:914116020118)
文摘An investigation on the magnetostructural transformation and magnetocaloric properties of Ni48-xCo2Mn38＋xSn12（x = 0, 1.0, 1.5, 2.0, and 2.5） ferromagnetic shape memory alloys is carried out. With the partial replacement of Ni by Mn in the Ni_（48）Co2Mn38Sn12 alloy, the electron concentration decreases. As a result, the martensitic transformation temperature is decreased into the temperature window between the Curie-temperatures of austenite and martensite. Thus, the samples with x = 1.5 and 2.0 exhibit the magnetostructural transformation between the weak-magnetization martensite and ferromagnetic austenite at room temperature. The structural transformation can be induced not only by the temperature,but also by the magnetic field. Accompanied by the magnetic-field-induced magnetostructural transformation, a considerable magnetocaloric effect is observed. With the increase of x, the maximum entropy change decreases, but the effective magnetic cooling capacity increases.
