外延RuO2薄膜中应变与Ti3+对反常霍尔效应贡献的分离
Disentangling Strain and Ti3+ Contributions to the Anomalous Hall Effect in Epitaxial RuO2 Films
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中文总结 AI 辅助
本研究通过Ti合金化RuO2异质结构分离应变与Ti3+贡献，发现仅Ti3+不足以产生反常霍尔效应，外延应变通过改变巡游电子结构成为主导控制参数。
中文摘要 AI 辅助
在外延RuO2/TiO2中报道的反常霍尔效应（AHE）被归因于应变稳定的磁态，但应变可能与Ru-Ti互混和界面电荷重新分布纠缠在一起，后者可产生Ti3+并可能形成局域磁矩。在此，我们利用Ti合金化的RuO2异质结构来分离这些贡献，在该结构中保留了丰富的Ti3+态，同时独立改变外延应变。应变薄膜和弛豫薄膜具有几乎相同的Ti/Ru组成和相当的Ti3+比例，然而，显著的非线性反常霍尔效应仅出现在相干应变薄膜中，而弛豫异质结构则表现出几乎线性的霍尔响应。光谱椭偏进一步表明，具有反常霍尔效应的应变态伴随着巡游电子响应的重构，包括金属性增强和更长的载流子弛豫时间。这些结果表明，仅形成Ti3+不足以产生反常霍尔态，并确定外延应变通过其对巡游RuO2电子结构的修饰，是主导的控制参数。
英文摘要
The anomalous Hall effect (AHE) reported in epitaxial RuO2/TiO2 has been attributed to a strain-stabilized magnetic state, but strain can be entangled with Ru-Ti intermixing and interfacial charge redistribution, which can produce Ti3+ and potentially localized moments. Here, we disentangle these contributions using Ti-alloyed RuO2 heterostructures in which abundant Ti3+ states are retained while epitaxial strain is independently changed. The strained and relaxed films have nearly identical Ti/Ru compositions and comparable Ti3+ fractions, yet a pronounced nonlinear AHE appears only in the coherently strained film, while the relaxed heterostructure exhibits an almost linear Hall response. Spectroscopic ellipsometry further shows that the AHE-active strained state is accompanied by a reconstruction of the itinerant electronic response, including enhanced metallicity and longer carrier relaxation times. These results show that Ti3+ formation alone is insufficient to generate the anomalous Hall state and identify epitaxial strain, through its modification of the itinerant RuO2 electronic structure, as the dominant control parameter.
发表机构
- University of Minnesota−Twin Cities（明尼苏达大学双城分校）
- Hankuk University of Foreign Studies（韩国外国语大学）
- Kyung Hee University（庆熙大学）
- Temple University（天普大学）
- Diamond Light Source Ltd.（钻石光源有限公司）
- Pacific Northwest National Laboratory（太平洋西北国家实验室）
机构由 AI 辅助整理，请以论文原文为准。
