Large low-field magnetocaloric effect in directionally solidified Ni55Mn18+xGa27-x (x=0, 1, 2) alloys
Large low-field magnetocaloric effect in directionally solidified Ni55Mn18+xGa27-x (x=0, 1, 2) alloys
复制标题
定向凝固 Ni55Mn18 xGa27-x (x=0, 1, 2) 合金中的大低场磁热效应
DOI：
10.1016/j.jmmm.2017.08.090
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发表时间：
2018
影响因子：
2.7
通讯作者：
Liang Zuo
中科院分区：
文献类型：
--
作者：
Zhenzhuang Li;Zongbin Li;Bo Yang;Yiqiao Yang;Yudong Zhang;Claude Esling;Xiang Zhao;Liang Zuo
The magnetostructural transformation and magnetocaloric effect of directionally solidified polycrystalline Ni55Mn18+xGa27−x(x = 0, 1, 2) alloys were studied. It is shown the directionally solidified alloys form coarse columnar-shaped grains with strong <0 0 1>A(the subscript A refers to austenite) preferred orientation along the solidification direction. Through Mn substitution for Ga, a coupled magnetostructural transformation was realized in Ni55Mn19Ga26and Ni55Mn20Ga25alloys. Large adiabatic temperature variation (ΔTad) of 1.47 K and 1.57 K under the low field change of 1.5 T were achieved in these two alloys, respectively. Such ΔTadvalues are obviously higher than that obtained from a single martensitic transformation and magnetic transition. The present results demonstrate that proper composition tuning to achieve magnetostructural transformation as well as increasing the grain size and preferential orientation degree through directional solidification could be an economical processing route to optimize magnetocaloric properties in polycrystalline Ni-Mn-Ga based alloys.
