溶液旋涂法制备Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜的自旋输运特性  

Spin transport properties of Bi_(x)Y_(3-x)Fe_(5)O_(12) thin films prepared by spin coating

作　　者：田颖异 王拴虎 罗殿柄 魏向洋 金克新[1] Tian Ying-Yi;Wang Shuan-Hu;Luo Dian-Bing;Wei Xiang-Yang;Jin Ke-Xin(School of Physical Science and Technology,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西北工业大学物理科学与技术学院,西安710072

出　　处：《物理学报》2023年第1期246-253,共8页Acta Physica Sinica

基　　金：陕西省自然科学基金(批准号:2020JM-088);陕西省自然科学基金重点研究项目(批准号:2021JZ-08)资助的课题。

摘　　要：钇铁石榴石(yttrium iron garnet,YIG)的自旋输运特性一直是自旋电子学的研究重点之一.Bi作为YIG最常见的掺杂元素,其薄膜Bi_(x)Y_(3-x)Fe_(5)O_(12)的磁光特性已经被广泛研究.但Bi^(3+)取代Y^(3+)对YIG自旋输运的影响规律还没有被系统地研究过.本文利用溶液旋涂法制备了不同掺杂比的Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜,并研究Bi掺杂对YIG薄膜形貌结构和自旋输运性能的影响.结果表明Bi掺杂没有改变YIG的晶体结构,掺杂比上升令薄膜的吸收强度增大,带隙减小.XPS表明了Bi^(3+)和Bi^(2+)的存在.Bi掺杂在自旋输运上的调控体现在Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜的磁振子扩散长度相比纯YIG薄膜有所减小.同时研究发现Pt/Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜中依然可以检测到明显的自旋霍尔磁电阻,并在x=0.3时振幅最大.Yttrium iron garnet(YIG),as a room temperature ferrimagnetic insulator with low damping and narrow ferromagnetic resonance linewidth,has been the research hotspot in spintronics because of its spin transport properties.Bi is one of the most common doping elements used in YIG,and some researches have proved that it can tune the magnetic properties of YIG.Previous studies of Bi_(x)Y_(3-x)Fe_(5)O_(12)thin films focused on the evolutions of their structures,morphologies,and magnetic characteristics.Yet,the effects of Bi^(3+)substitution of Y^(3+)on spin transport in YIG thin films have not been systematically studied.The regulation of YIG spin transport by doping is expected to provide a new idea for the spintronics exploration of Pt/YIG system.In this work,we prepare a series of Bi_(x)Y_(3-x)Fe_(5)O_(12)films with different doping ratios by spin coating.And we investigate the effects of Bi3+on morphology,structure and spin transport properties of YIG films.The results show that Bi doping does not change the crystal structure of YIG.The absorption of the film increases and the bandgap decreases with the increase of doping ratio.The X-ray photoelectron spectroscopy(XPS)indicates the coexistence of Bi^(3+)and Bi^(2+).The regulation of Bi doping on spin transport is reflected in the fact that the magnon diffusion length of Bi_(x)Y_(3-x)Fe_(5)O_(12)films is significantly smaller than that of pure YIG films.Meanwhile,we find that the obvious spin Hall magnetoresistance can still be detected in the Pt/Bi_(x)Y_(3-x)Fe_(5)O_(12)heterostructure,and the amplitude is the largest when x=0.3.

关 键 词：钇铁石榴石 Bi掺杂 自旋输运 溶液旋涂法 

分 类 号：O469[理学—凝聚态物理]