取向生长稀土基软磁薄膜的磁性及穆斯堡尔谱研究

Soft magnetic thin films have been widely used in the field of electronic devices. However, the widely used ferrite soft magnetic films have been unable to meet the requirements of higher and higher working frequencies of these electronic devices. Therefore, it is utmost important to study new type of soft magnetic films that can be used in higher frequency bands. Based on our previous work, we show theoretically that oriented-growth planar type rare earth based soft magnetic thin films should have better high frequency properties than all the soft magnetic films currently in use. Therefore, we propose to grow oriented rare earth based soft magnetic films with better high frequency properties in this project. By using the combination of both macro- and micro-magnetic measurements, we will investigate the relationship between macro-magnetic properties and the micro-structure and micro-magnetic properties to get a better understanding of the anisotropy mechanism of the material and to optimize the measurement methods of the effective magnetic anisotropy field. We hope, in the end of this project, that we can gain full control of the high frequency properties of our soft magnetic films and provide better support for future applications of these thin films from both thoretical and experimental point of view.

软磁薄膜材料在电子器件构筑领域具有非常广泛的应用。然而，目前广泛应用的铁氧体软磁薄膜已无法满足电子器件越来越高的工作频率之要求。因此，研究可用于更高频段的新型软磁薄膜并掌握其制备工艺至关重要。在本课题组前期工作的基础上，我们从理论上证明取向生长的易面型稀土基软磁薄膜拥有比目前应用的所有软磁薄膜更加优越的高频磁性。因此，本项目计划研究稀土基软磁薄膜的取向生长工艺，得到具有更优高频性能的软磁薄膜；结合宏观、微观磁性测量手段，深入研究薄膜的宏观磁性、微结构及微观磁性之间的关系，掌握材料的各向异性机理，优化薄膜样品有效各向异性场测量方法等，为实现可自由调控薄膜高频性能及其在相关电子器件构筑等领域中的具体应用提供理论依据和实验基础。

软磁薄膜材料在电子器件构筑领域具有非常广泛的应用。然而，目前广泛应用的铁氧体软磁薄膜已无法满足电子器件越来越高的工作频率之要求。因此，研究可用于更高频段的新型软磁薄膜并掌握其制备工艺至关重要。穆斯堡尔谱具有极高的能量分辨率及良好的局域特点，可以得到测试样品的价态、自旋态、晶格对称性及局域磁性等多种内禀特性；因此，在本课题组前期工作的基础上，我们利用磁控溅射的方法制备了取向生长的具有负磁晶各向异性的软磁薄膜。具体研究了 CoIr、Sm2Fe14B, Nd2Fe17, Nd2Co17 及 Y2Co17 体系的制备条件对薄膜取向生长的影响；研究了薄膜厚度、掺杂、退火及注氢对薄膜性质的影响。利用穆斯堡尔谱结合宏观磁性测量深入研究了薄膜的微观结构与微观磁性，研究了材料的磁晶各向异性机理。同时，我们还探索了穆斯堡尔谱在铁基超导材料研究领域的应用，研究了 RbLn2Fe4As4O2 (Ln=Tb, Dy 及 Ho)体系的微观磁性及 Eu0.8La0.2FeAs2 超导体的自旋密度波。经过本项目的研究，我们掌握了 CoIr、Sm2Fe14B, Nd2Fe17, Nd2Co17 及 Y2Co17 体系软磁薄膜的制备工艺，并实现了对其高频磁性的调控与优化。掌握了此类软磁薄膜的宏观与微观磁性表征方法，得到了材料的磁晶各向异性机理，可以为自由调控薄膜高频磁性及实现其在相关电子器件领域的应用提供理论依据和实验基础。