Abstract Current research on magnetocaloric materials (MCM) aims at developing low cost, environmentally friendly materials which can be manufactured by simple processes. We report the effect of high energy ball milling on the structural, magnetic and magnetocaloric properties of low cost Fe2.1Cr0.9Al alloys. The degree of structural order in the Fe-Cr sublattice was found to vary with milling time in a cyclic fashion at a milling speed of 600 rpm. This phenomenon was analyzed by a reaction rate model based on the stored energy during high energy milling. The sample possessed a B2 crystal structure before milling. Milling for 15 min. at 600 rpm induced structural changes to produce a L21 structure. Interestingly, the 15 min. milled sample exhibited ∼50% higher saturation magnetization (MS) compared to the value before milling. The relative cooling power (RCP) also increased to 300 Jkg−1 at 5 T, compared to a value of 244 Jkg−1 before milling. Extended X-ray absorption fine structure (EXAFS) studies revealed the emergence of short range order in the milled samples.

中文翻译：

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高能球磨在 Fe2.1Cr0.9Al 磁热合金中引起的循环结构有序

摘要 目前对磁热材料（MCM）的研究旨在开发可通过简单工艺制造的低成本、环保材料。我们报告了高能球磨对低成本 Fe2.1Cr0.9Al 合金的结构、磁性和磁热性能的影响。在 600 rpm 的研磨速度下，Fe-Cr 亚晶格中的结构有序度随着研磨时间以循环方式变化。这种现象通过基于高能研磨过程中储存的能量的反应速率模型进行分析。样品在研磨前具有 B2 晶体结构。研磨15分钟。在 600 rpm 时诱导结构变化以产生 L21 结构。有趣的是，15 分钟。与研磨前的值相比，研磨后的样品表现出约 50% 的饱和磁化强度 (MS)。与铣削前的 244 Jkg-1 值相比，相对冷却功率 (RCP) 在 5 T 时也增加到 300 Jkg-1。扩展 X 射线吸收精细结构 (EXAFS) 研究揭示了研磨样品中出现了短程有序。