Structurally Heterogeneous Model of Extrinsic Magnetostriction for Fe-Ga and Similar Magnetic Alloys: Part I. Decomposition and Confined Displacive Transformation
Structurally Heterogeneous Model of Extrinsic Magnetostriction for Fe-Ga and Similar Magnetic Alloys: Part I. Decomposition and Confined Displacive Transformation
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DOI：
10.1007/s11661-007-9253-z
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发表时间：
2007-07
期刊：
影响因子：
--
通讯作者：
A. Khachaturyan;D. Viehland
中科院分区：
文献类型：
--
作者：
A. Khachaturyan;D. Viehland
建立了铁磁合金的组成和结构非均质模型，并应用于具有巨磁致伸缩的Fe-Ga合金。我们的模型假设，接近其溶解度极限的Fe-Ga bcc固溶体是do3相的抗粗化纳米分散体，这是由于过量空位引起的相干性提升而形成的，就像化学性质相似的Fe-Al合金一样。这种非均相状态经历了立方→四方的位移转变，使结构更接近平衡的基于fcc的l12有序相。我们的理论预测与现有的电子显微镜和x射线衍射观测相一致。
A compositionally and structurally heterogeneous model for ferromagnetic alloys has been developed and applied to Fe-Ga alloys that exhibit giant magnetostriction. Our model assumes that the Fe-Ga bcc solid solution near its solubility limit is a coarsening-resistant nanodispersion of a DO3phase that is formed due to coherency lifting by excess vacancies, as is known to be the case for chemically similar Fe-Al alloys. This compositionally heterogeneous state undergoes a cubic → tetragonal displacive transformation that brings the structure closer to an equilibrium fcc-based L12ordered phase. The predictions of our theory are in agreement with existing electron microscopy and X-ray diffraction observations.