Characterization of YIG thin films and vacuum annealing effect by polarized neutron reflectometry and magnetotransport measurements
Characterization of YIG thin films and vacuum annealing effect by polarized neutron reflectometry and magnetotransport measurements
复制标题
通过偏振中子反射计和磁输运测量表征 YIG 薄膜和真空退火效应
DOI：
10.1063/1.5124832
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发表时间：
2019-10-28
影响因子：
4
通讯作者：
Cai, J. W.
中科院分区：
文献类型：
--
作者：
Bai, He;Zhan, X. Z.;Cai, J. W.
在(111)Gd3Ga5O12衬底上外延生长了纳米厚的Y3Fe5O12(YIG)薄膜，通过偏振中子反射率和磁化强度测量对薄膜的磁死区厚度进行了测量。YIG在300-400℃的真空退火使YIG/铂双层膜的反常霍尔效应、自旋霍尔磁阻和自旋泵浦显著降低，但使自旋塞贝克效应大大增强。结构、静态和动态磁测量表明，退火对YIG薄膜的整体氧化态和饱和磁化强度没有明显影响，但引入了可能以氧空位形式存在的细微缺陷。这项研究表明，YIG薄膜中的细微缺陷对自旋输运特性有多方面的影响，在真空中进行YIG薄膜的退火时应谨慎行事。
Nanometer-thick Y3Fe5O12 (YIG) films epitaxially grown on (111) Gd3Ga5O12 with a magnetic dead layer as thin as about 1.2 nm are quantified by polarized neutron reflectivity and magnetization measurements. Vacuum annealing on YIG at 300-400 degrees C leads to substantial reduction in the anomalous Hall effect, spin Hall magnetoresistance, and spin pumping in YIG/Pt bilayers but causes large enhancement in the spin Seebeck effect. The structural, static, and dynamic magnetic measurements show that the annealing has no discernible influence on the global oxidization states and saturation magnetization of YIG films but introduces subtle defects possibly in the form of oxygen vacancies. This study suggests that subtle defects in thin YIG films have multiple effects on the spin transport properties, and caution should be taken in annealing YIG in vacuum.