Magnetocaloric effect of compositionally partitioned Mn5−xGe3Nix alloys produced by solid state sintering
Magnetocaloric effect of compositionally partitioned Mn5−xGe3Nix alloys produced by solid state sintering
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DOI：
10.1016/j.jallcom.2016.04.258
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发表时间：
2016-10
影响因子：
6.2
通讯作者：
K. Kang;Y. Oh;Ju Hwan Kim;Eun Jeong Kim;H. Kim;C. Yoon
中科院分区：
文献类型：
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作者：
K. Kang;Y. Oh;Ju Hwan Kim;Eun Jeong Kim;H. Kim;C. Yoon
合成了Mn 5 − xGe 3 Nix（x= 0，0.05，0.1）合金粉末，研究了Ni取代对Mn 5Ge 3磁热效应的影响。通过控制烧结时间，有意地将组成不均匀性引入烧结样品中以形成准稳态复合物状结构。这种成分分区结构使三种不同成分合金的Δ SM-T曲线相结合，从而提供了一种优化Δ SM-T曲线形状和制冷量的方法。烧结后的Mn 5 − xGe 3 Nix合金的制冷量为43 J kg−1，熵变峰值为282 K，ΔH= 1 T时的工作温度范围为32 K，可能适用于室温磁制冷。结果表明，烧结粉末的脆性样品具有不同的组成，同时最大限度地减少组成均匀化，可用于工程的制冷剂的磁热性能，并在同一时间，以获得所需的物理形状。
Mn5−xGe3Nix(x= 0, 0.05, 0.1) alloy powders were synthesized to evaluate the effect of the Ni substitution on the magnetocaloric effect (MCE) of Mn5Ge3.Equi-molar mixture of the three powder samples was consolidated into a mechanically sturdy form through solid state sintering. By controlling the sintering period, compositional non-uniformity was intentionally introduced into the sintered sample to form a quasi-steady state composite-like structure. The compositionally partitioned structure enabled combining ΔSM–Tcurves from the alloys with the three different compositions, hence, providing a means to optimize the shape of the ΔSM–Tcurve and the refrigeration capacity. The sintered Mn5−xGe3Nixalloy produced a refrigeration capacity of 43 J kg−1, peak entropy change at 282 K, and operating temperature range of 32 K under ΔH= 1 T which are possibly suitable for room-temperature magnetic refrigeration. It was demonstrated that sintering powders of brittle samples with different compositions while minimizing compositional homogenization can be used to engineer the magnetocaloric properties of the refrigerant and, at the same time, to obtain desired physical shapes.