Abstract The vanadium oxide thin films of both VO2 (V4+) and V2O3 (V3+) are phase-selectively synthesized on atomically stepped α-Al2O3 (0001) substrates by pulsed laser deposition of an amorphous precursor VxOy (V5+) phase at room-temperature, and subsequent uniaxial compressive annealing (UCA) at at 773 K under vacuum conditions. The thin films are epitaxially crystallized under uniaxial pressure, however, the process produces randomly oriented VO2-based polycrystalline when compression is not used. The VO2 (010) epitaxial film can be obtained under an applied pressure of 1 MPa; further, the V2O3 (0001) epitaxial film is formed under a pressure of more than 10 MPa. The epitaxial films indicate a distinct metal-insulator transition in which the resistivity is varied by 103 in accordance with the ρ-T measurement, i.e., the transition temperature (TC) is estimated to be ∼350 K for VO2 thin films crystallized under a pressure of 1 MPa, and ∼150 K and ∼120 K for V2O3 thin films formed under 10 and 30 MPa, respectively. Additional sequential UCA with distinct pressures of 1, 10, and 1 MPa again reveals a corresponding and reversible phase transformation between VO2 and V2O3 with consistent resistivity variation. Therefore, pressure-induced topotaxy can be proved in both the phases. The obtained epitaxial thin films demonstrate a relatively flat surface with a root-mean square roughness of

中文翻译：

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蓝宝石上 VO2 和 V2O3 薄膜的固相外延和压力诱导拓扑在单轴压缩下使用退火

摘要 VO2 (V4+) 和 V2O3 (V3+) 的氧化钒薄膜是在室温下通过脉冲激光沉积非晶前驱体 VxOy (V5+) 相在原子阶梯状 α-Al2O3 (0001) 衬底上进行相选择性合成的，随后在真空条件下在 773 K 下进行单轴压缩退火 (UCA)。薄膜在单轴压力下外延结晶，然而，当不使用压缩时，该过程会产生随机取向的基于 VO2 的多晶。在1 MPa的外加压力下可得到VO2(010)外延膜；进一步地，在大于10MPa的压力下形成V2O3(0001)外延膜。外延膜显示出明显的金属-绝缘体转变，其中电阻率根据 ρ-T 测量值变化了 103，即，在 1 MPa 压力下结晶的 VO2 薄膜的转变温度 (TC) 估计为 ~350 K，而对于在 10 和 30 MPa 压力下形成的 V2O3 薄膜，转变温度 (TC) 估计分别为 ~150 K 和 ~120 K。具有 1、10 和 1 MPa 不同压力的附加连续 UCA 再次揭示了 VO2 和 V2O3 之间相应的可逆相变，并具有一致的电阻率变化。因此，可以在两个阶段中证明压力诱导拓扑。获得的外延薄膜表面相对平坦，均方根粗糙度为 1 MPa 再次揭示了 VO2 和 V2O3 之间相应的可逆相变，并具有一致的电阻率变化。因此，可以在两个阶段中证明压力诱导拓扑。获得的外延薄膜表面相对平坦，均方根粗糙度为 1 MPa 再次揭示了 VO2 和 V2O3 之间相应的可逆相变，并具有一致的电阻率变化。因此，可以在两个阶段中证明压力诱导拓扑。获得的外延薄膜表面相对平坦，均方根粗糙度为