铁单质薄膜磁致伸缩行为与磁矩演化研究

磁致伸缩材料在传感器、位移器件等领域应用前景广阔,对此类材料的制备与实验已成为研究热点,但使用分子动力学方法模拟其磁致伸缩过程中内部磁矩的演化仍缺乏相关研究.本研究以磁致伸缩材料铁单质为研究对象,采用分子动力学方法建立单畴铁单质磁致伸缩模型.分析了铁单质薄膜磁致伸缩行为随初始磁矩的变化,以及在磁场作用下微观原子磁矩的变化与宏观磁致伸缩之间的关系.结果表明:模型磁化构型的演化与磁致伸缩行为有着密切联系,随着外加磁场强度增大,原子磁矩与外加磁场方向相同的区域面积逐渐增大,宏观表现为模型的磁致伸缩随磁场强度增大而伸长,并最终达到饱和,而边界处的原子磁矩是模型是否达到饱和磁致伸缩的关键.

Magnetostrictive behavior and magnetic moment evolution of iron thin films

Magnetostrictive materials have broad application prospects in the fields of sensors and displacement devices, and the preparation and experiment of such materials have become a research hotspot. However, the evolution of internal magnetic moment during magnetostrictive process using molecular dynamics method is still lacking.In this study, the magnetostrictive iron elemental material was used as the research object, and the single-domain iron elemental magnetostrictive model was established by molecular dynamics method.The variation of the magnetostrictive behavior of iron thin film with the initial magnetic moment and the relationship between the variation of the magnetic moment of the microscopic atom and the macroscopic magnetostrictive behavior under the action of magnetic field are analyzed. Results show that the evolution of the model magnetization configuration is closely related to the magnetostriction behavior, with the increasing strength of magnetic field, the area of the region with the same direction of the atomic magnetic moment and the applied magnetic field increases gradually, macro performance is that the magnetostriction of the model elongates with the increase of magnetic field strength, and eventually reaches saturation. The atomic magnetic moment at the boundary is the key to the saturation magnetostriction of the model.