VO_x films were deposited by radio-frequency reactive magnetron sputtering from a vanadium target at room temperature. Local atomic and electronic structures of the films were then modified by thermal annealing. The oxidation state and structural and gasochromic properties of the films were elucidated by X-ray absorption spectroscopy. Analytical results indicate that the as-deposited VO_x films were amorphous with mixed V~(4+) and V~(5+) valences. The amorphous VO_x had a disordered and expanded lamellar structure resembling that of polymer-intercalated V2O5 gels. VO_x films were crystallized into orthorhombic V2O5 at 300 °C, and the lamellar structure was eliminated at 400 °C. Additionally, the gasochromic reaction reduced the vanadium valence via intervalence transitions between V~(5+) and V~(3+) . Moreover, removing the lamellar structure reduced the gasochromic rate, and the gasochromic reaction transformed the V2O5 crystalline phase irreversibly into an H_(143)VO5 phase. Based on the results of this study, amorphous VO_x with a lamellar structure is recommended for use in H2 gas sensors.
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机译：在室温下通过射频反应磁控溅射从钒靶上沉积VO_x膜。然后通过热退火改性膜的局部原子和电子结构。通过X射线吸收光谱阐明了膜的氧化态以及结构和气致变色性质。分析结果表明，沉积的VO_x薄膜为非晶态，具有混合的V〜（4+）和V〜（5+）价。无定形VO_x具有类似于聚合物插入的V 2 O 5凝胶的无序且膨胀的层状结构。 VO_x薄膜在300°C下结晶为正交晶V2O5，在400°C下消除层状结构。另外，气致变色反应通过V〜（5+）和V〜（3+）之间的间隔跃迁降低了钒价。此外，去除层状结构降低了气致变色速率，并且气致变色反应将V 2 O 5结晶相不可逆地转化为H_（143）VO 5相。根据这项研究的结果，建议将具有层状结构的无定形VO_x用于H2气体传感器。
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