近日，课题组博士生苟峻铭同学的一篇论文“Large and sensitive magnetostriction in ferromagnetic composites with nanodispersive precipitates ”被NPG Asia Materials录用。这是他作为第一作者在磁致伸缩材料领域发表的第6篇论文。祝贺他！

Abstract

Large and sensitive magnetostriction (large strain induced by small magnetic fields) is highly desired for applications of magnetostrictive materials. However, it is difficult to improve magnetostriction and to reduce switching field simultaneously because both the magnetostriction and switching field are proportional to the magnetocrystalline anisotropy. To solve this fundamental challenge, here we report that introducing tetragonal nanoprecipitates into cubic matrix can facilitate large and sensitive magnetostriction even in random polycrystals. As exhibited in a proof-of-principle reference, Fe-Ga alloys, the figure of merit defined by saturation magnetostriction over magnetocrystalline anisotropy constant can be enhanced by over 5 times through aging the solution-treated precursor. The aging-induced nanodispersive face-centered-tetragonal (FCT) precipitates, on one hand, create local tetragonal distortion of the body-centered-cubic (BCC) matrix, substantially enhancing the saturation magnetostriction to be comparable to that of single crystal materials, on the other hand, randomly couple with the matrix at nanoscale, resulting in the collapse of net magnetocrystalline anisotropy. Our findings not only provide a simple and feasible approach to enhance the magnetostriction performance of random polycrystalline ferromagnets but also add important insights into understanding the mechanism of heterogeneous magnetostriction.