The correlation between electronic properties and epitaxial strain in a cation‐deficient system has rarely been investigated. Cation‐deficient SrVO₃ films are taken as a model system to investigate the strain‐dependent electrical and electronic properties. Using element‐ and charge‐sensitive soft X‐ray absorption, V L‐edge absorption measurements have been performed for Sr_1–yVO₃ films of different thicknesses capped with 4 u.c. (unit cell) SrTiO₃ layers, showing the coexistence of V⁴⁺ and V⁵⁺ in thick films. A different correlation between V valence state and epitaxial strain is observed for Sr_1–yVO₃ ultrathin films, i.e. a variation in V valence state is only observed for tensile‐strained films. Sr_1–yVO₃ thin films are metallic and exhibit a thickness‐driven metal–insulator transition at different critical thicknesses for tensile and compressive strains. The asymmetric response of electrical conductivity to strain observed in cation‐deficient Sr_1–yVO₃ films will be beneficial for functional oxide electronic devices.

中文翻译：

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基于在V L2和L3边缘的吸收测量，在缺乏阳离子的Sr1-yVO3超薄膜中，电导率和V价态对应变的不对称响应。

很少研究阳离子不足系统中电子性质与外延应变之间的相关性。阳离子不足的SrVO ₃薄膜作为模型系统研究了应变相关的电学和电子性能。使用对元素和电荷敏感的软X射线吸收，对不同厚度的Sr _{1 – y} VO ₃膜进行了V L边缘吸收测量，并覆盖了4 uc（晶胞）SrTiO ₃层，表明V共存厚膜中为⁴⁺和V ⁵⁺。对于Sr _{1 – y} VO ，V价态与外延应变之间存在不同的相关性_3个超薄薄膜，即仅在拉伸应变薄膜上观察到V价态的变化。Sr _{1- y} VO ₃薄膜是金属的，并且在拉伸和压缩应变的不同临界厚度下表现出厚度驱动的金属-绝缘体转变。在阳离子不足的Sr _{1 – y} VO ₃薄膜中观察到的电导率对应变的不对称响应将对功能性氧化物电子器件有益。