Large inverse magnetocaloric effect and magnetoresistance in nickel rich Ni 52 Mn 34 Sn 14 Heusler alloy
Large inverse magnetocaloric effect and magnetoresistance in nickel rich Ni 52 Mn 34 Sn 14 Heusler alloy
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DOI：
10.1016/j.jmmm.2014.02.023
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发表时间：
2014-06
影响因子：
2.7
通讯作者：
D. Pal;A. Ghosh;K. Mandal
中科院分区：
文献类型：
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作者：
D. Pal;A. Ghosh;K. Mandal
采用电弧熔炼和退火均匀化工艺制备了富镍Ni 52 Mn 34 Sn 14 Heusler合金。一级磁结构转变（FOMST）的存在被各种测量所证实。与传统的Ni 50 − xMn 36 + xSn 14合金相比，在马氏体相变温度附近，由于分别改变3 T和8 T磁场，观察到较大的磁熵变（麦克斯韦热力学方程的磁熵变为<$SM <$8 J/kg K，Clasius-Clapeyron方程的磁熵变为<$SM <$18 J/kg K）和较大的负磁阻（MR <$30%）。通过考虑其他研究人员报道的其他更接近的成分来讨论过量Ni含量的影响。在FOMST由于动力学逮捕的不可逆性进行了研究，从MR与磁场曲线在一个单一的温度在两个不同的初始阶段。用各种磁性测量方法研究了该合金的交换偏置行为。
Nickel rich Ni52Mn34Sn14Heusler alloy was prepared by arc melting and subsequent homogenization by annealing. Existence of first order magneto-structural transition (FOMST) was confirmed by various measurements. In comparison to conventional Ni50−xMn36+xSn14alloys, a larger magnetic entropy change (∆SM≈8 J/kg K using Maxwell׳s thermodynamic equation and ∆SM≈18 J/kg K using Clasius–Clapeyron equation) and large negative magnetoresistance (MR≈−30%) were observed in the vicinity of martensitic transition temperature due to a change of 3 T and 8 T magnetic fields respectively. Effect of excess Ni content was discussed by considering other nearer compositions as reported by other researchers. Irreversibility in FOMST due to kinetic arrest was also studied from MR vs magnetic fields curves taken at a single temperature in two different initial phases. The exchange bias behavior in this alloy was studied by various magnetic measurements.