Microstructure, magnetic and magnetocaloric properties in magnetic-field-induced martensitic transformation Mn1−xCo1+xGe alloy ribbons

Publication date: Available online 19 April 2019Source: Physics Letters AAuthor(s): Chicheng Ma, Qing Ge, Kai Liu, Nan Ye, Jiancheng TangAbstractThe sharp field-induced metamagnetic martensitic transformation plays a pivotal role in magnetoresponsive effects for ferromagnetic shape memory alloys (FSMAs). Homogeneous polycrystalline Mn1−xCo1+xGe alloy ribbons are prepared by using the arc-melting and melt-spinning technique in this work. The microstructure, crystalline structure, magnetic and magnetocaloric properties are studied in these ribbons. The substitution of Co for Mn reduces the structural transformation temperature, which leads to the realization of coincident magnetostructural transformation. Strikingly, a magnetic-field-induced martensitic transformation is observed in these ribbons. Therefore, large magnetocaloric effect, including maximum magnetic entropy change (ΔSM,max) value of ∼28 and 25 Jkg−1K−1 and effective refrigeration capacity (RCeff) of ∼168 and 181 Jkg−1 are obtained for x=0.035 and 0.09 samples, respectively, under the field change of μ0ΔH=0–7T. Furthermore, the average hysteresis loss of these ribbons reduces largely in contrast to their bulk counterparts. These results would provide the new experimental data for magnetic refrigerant materials and pave the way for the further investigation of other FSMAs.

Source: Physics Letters A - April 20, 2019 Category: Physics Source Type: research