新型VO_2相变薄膜的制备

采用离子束溅射和退火工艺制备了一种新的相变型薄膜VO2。此种薄膜的方块电阻为120～148kΩ,电阻-温度关系曲线显示该薄膜的相变温度接近室温。SEM分析表明,所制备的薄膜致密均匀。样品的明场透射电子显微图像显示,制备的薄膜是多晶薄膜,晶粒尺寸达到纳米数量级。XRD分析表明,该薄膜的成分中除了含有VO2外,还含有V2O5,说明该工艺制备的是含有VO2的混合物,而不是纯VO2薄膜。

Preparation of novel VO2 phase-transition thin films

A novel low temperature switch material VO2 thin film was fabricated by ion-sputtering and annealing. The sheet resistance of the thin films obtained was measured to be in a range of 120～148 kΩ. Temperature coefficient of resistance(TCR)at room tempoerature was calculated from the relationaship curve of temperature-resistance of the VO2 films. Its found that the films have phase-transition temperature decreased nearly by room temperature. Scanning electron microscope(SEM)micrographs show that the thin films are smooth and compact. The bright field tunneling electron microscope(TEM)image shows that the novel VO2 thin films contained of polycrystalline nanocrystal. X-ray diffraction(XRD)measurement makes it clear that the thin films contain V2O5 except for VO2 rather than VO2 only.