Correlating the Nanoscale Structural, Magnetic, and Magneto-Transport Properties in SrRuO3-Based Perovskite Thin Films: Implications for Oxide Skyrmion Devices
Correlating the Nanoscale Structural, Magnetic, and Magneto-Transport Properties in SrRuO3-Based Perovskite Thin Films: Implications for Oxide Skyrmion Devices
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DOI：
10.1021/acsanm.9b01918
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发表时间：
2020-02-01
影响因子：
5.9
通讯作者：
Eng, Lukas M.
中科院分区：
文献类型：
--
作者：
Malsch, Gerald;Ivaneyko, Dmytro;Eng, Lukas M.
研究了SrRuO 3（SRO）超导薄膜和SrRuO 3/SrIrO 3/SrZrO 3超导薄膜的结构和磁性（SRO/SIO/SZO：RIZ）三层异质结的磁光克尔效应（MOKE）和磁输运的宏观数据进行比较（反常霍尔效应：AHE），当应用非接触式扫描力显微镜（nc-SFM）和磁力显微镜（MFM）时具有纳米级指纹。SRO和RIZ薄膜在650 ℃下外延生长到邻位SrTiO 3（100）单晶衬底上，标称厚度分别为4和4/2/2晶胞（uc）。我们的相关分析允许关联的地形样本功能的过度生长的个别层，他们的剩余磁化强度，如这里所示的是相关的解释宏观AHE数据。虽然在AHE的驼峰状功能表明磁纹理skyrmion相存在约55 K与拓扑霍尔效应（THE），我们的MOKE和MFM的数据不能支持这一理论的研究薄膜。相比之下，我们的SFM/MFM局部尺度分析发现，局部矫顽场强烈依赖于SRO和RIZ样品中的有效层厚度和化学计量比，对局部能带结构产生巨大影响。事实上，正是这些变化反过来通过AHE电阻率回路中的异常来模拟潜在的THE。
We investigated the structural and magnetic properties of bare SrRuO3 (SRO) ultrathin films and SrRuO3/SrIrO3/SrZrO3 (SRO/SIO/SZO: RIZ) trilayer heterostructures between 10 and 80 K, by comparing macroscopic data using the magneto-optical Kerr effect (MOKE) and magneto-transport (anomalous Hall effect: AHE), with nanoscale fingerprints when applying noncontact scanning force microscopy (nc-SFM) and magnetic force microscopy (MFM). SRO and RIZ ultrathin films were epitaxially grown at 650 degrees C onto vicinal SrTiO3 (100) single-crystalline substrates to a nominal thickness of 4 and 4/2/2 unit cells (uc), respectively. Our correlated analysis allows associating topographic sample features of overgrown individual layers to their residual magnetization, as is shown here to be relevant for interpreting the macroscopic AHE data. Although the hump-like features in the AHE suggest a magnetically textured skyrmion phase to exist around 55 K associated with the topological Hall effect (THE), both our MOKE and MFM data cannot support this theory for the ultrathin films investigated. In contrast, our SFM/MFM local-scale analysis finds the local coercive field to be strongly dependent on the effective layer thickness and stoichiometry in both the SRO and RIZ samples, with a huge impact on the local band structure. In fact, it is these variations that in turn mimic a potential THE through anomalies in the AHE resistivity loops.