Large inverse magnetic entropy changes and magnetoresistance in the vicinity of a field-induced martensitic transformation in Ni50−xCoxMn32−yFeyGa18
Large inverse magnetic entropy changes and magnetoresistance in the vicinity of a field-induced martensitic transformation in Ni50−xCoxMn32−yFeyGa18
复制标题
DOI：
10.1063/1.3467460
复制
发表时间：
2010-08
影响因子：
4
通讯作者：
A. Pathak;I. Dubenko;H. Karaca;S. Stadler;N. Ali
中科院分区：
文献类型：
--
作者：
A. Pathak;I. Dubenko;H. Karaca;S. Stadler;N. Ali
在Ga基磁性形状记忆合金Ni50−xCoxMn32−yFeyGa18的逆马氏体相变中观察到了显著的逆磁熵变（ΔSM）和磁阻（MR）。合金在300 K时的晶体结构为四方晶系，相变温度和磁性能与四方晶系畸变程度有关。当x=8和y=2时，H=5 T时ΔSM和MR的最大峰值分别为Δ（+）31 J Kg−1 K−1和Δ（+）21%。在该系统中观察到的相对小的滞后损失和大的制冷容量使得这些化合物具有应用前景。
Significantly large inverse magnetic entropy changes (ΔSM) and magnetoresistance (MR) were observed at the inverse martensitic phase transitions of the Ga-based magnetic shape memory Heusler alloys: Ni50−xCoxMn32−yFeyGa18. The crystal structures of alloys were tetragonal at 300 K and the phase transition temperatures and magnetic properties were found to be correlated with the degree of tetragonal distortion. The maximum peak values of the ΔSM and MR at H=5 T were determined as ≈(+)31 J Kg−1 K−1 and ≈−21%, respectively, for x=8 and y=2. The relatively small hysteretic loss and large refrigeration capacity observed in this system make these compounds promising materials for applications.