Transition metal oxide films exhibit strong structure-property correlations, which foster innovative physical properties that are not present in their bulk counterparts. This study has successfully prepared different thickness-dependent epitaxial Ti₂O₃ thin films on MgO (001) single crystal substrate using the pulsed laser deposition method. The results reveal a strong correlation between the crystal structure and superconductivity in Ti₂O₃ thin films. Synchrotron x-ray diffraction and high resolution transmission electron microscope measurements confirmed that the appearance of superconductivity is closely related to the coexistence of the cubic-Ti₂O₃ (γ-Ti₂O₃) and orthorhombic-Ti₂O₃ (o-Ti₂O₃) phases. Superconductivity is absent in 80 nm film, which exhibits only a single γ-Ti₂O₃ phase. The highest superconducting transition temperature (T _C) ∼ 7.2 K is achieved in 1200 nm film, which shows about 55% o-Ti₂O₃ phase and 45% γ-Ti₂O₃ phase. Room temperature Raman data suggest that E _g modes at ∼330 and ∼430 cm⁻¹ may associate with superconductivity, and an E _g mode at ∼660 cm⁻¹ is related to the insulating behavior observed in 80 nm film.

中文翻译：

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MgO 衬底上 Ti2O3 薄膜的超导性

过渡金属氧化物薄膜表现出很强的结构-性能相关性，这促进了其本体对应物中不存在的创新物理特性。本研究采用脉冲激光沉积法在MgO(001)单晶衬底上成功制备了不同厚度的外延Ti ₂ O _3薄膜。结果表明，Ti ₂ O ₃薄膜的晶体结构与超导性之间存在很强的相关性。同步加速器X射线衍射和高分辨率透射电子显微镜测量证实，超导性的出现与立方Ti ₂ O ₃ (γ-Ti ₂ O ₃ ) 和正交-Ti ₂ O ₃ (o-Ti ₂ O ₃ ) 相。80 nm 薄膜不存在超导性，仅表现出单一γ-Ti ₂ O ₃相。最高超导转变温度（吨 _C ) ∼ 7.2 K 在 1200 nm 薄膜中达到，显示大约 55% o-Ti ₂ O ₃相和 45%γ-Ti ₂ O ₃相。室温拉曼数据表明乙 ^{~330 和~430 cm -1处的}_g模式可能与超导性相关，并且乙 ^{~660 cm -1处的}_g模式与在 80 nm 薄膜中观察到的绝缘行为有关。