In situ growth of sol-gel-derived nano-VO2 film and its phase transition characteristics
In situ growth of sol-gel-derived nano-VO2 film and its phase transition characteristics
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溶胶凝胶法纳米VO2薄膜的原位生长及其相变特性
DOI：
10.1007/s11051-014-2656-z
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发表时间：
2014
影响因子：
2.5
通讯作者：
Yanyan Hu
中科院分区：
文献类型：
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作者：
Qiwu Shi;Wanxia Huang;Tiecheng Lu;Fang Yue;Yang Xiao;Yanyan Hu
我们报道了用无机溶胶-凝胶法沉积vo2薄膜的生长，然后进行后退火。观察了不同退火温度（300、500和700°C退火90 min）、退火次数（500°C退火20、40、60和90 min）和薄膜厚度（30、150和320 nm）下薄膜晶粒尺寸的原位演变。结果表明：溶胶-凝胶生成的vo2薄膜的晶粒尺寸分布受成核中心密度的调节，在退火过程中，成核中心密度随热变形程度的不同而变化。将薄膜厚度从30 nm增加到320 nm，可以形成晶粒尺寸分布均匀的致密纳米结构。结果表明，在较厚的vo2薄膜中，原位演化的纳米结构会导致相变的阈值温度降低，相变强度增强。讨论了纳米级晶粒尺寸对vo2薄膜下相变温度的影响。
We reported the growth of VO2film deposited by an inorganic sol–gel method, followed by post-annealing. An in situ evolution of the grain size in the films with different annealing temperatures (300, 500, and 700 °C for 90 min), annealing times (500 °C for 20, 40, 60, and 90 min), and film thicknesses (30, 150 and 320 nm) was observed. The results indicated that the grain size distribution in the sol–gel-derived VO2films was mediated by the density of nucleation center, which was varied in the films with different extents of thermal deformation during the annealing. By increasing the film thickness from 30 to 320 nm, a compact nanostructure with uniform distribution of grain size could be formed. It suggested that the in situ-evolved nanostructure in the thicker VO2film will lead to lower threshold temperature and enhanced transition intensity in the phase transition. The effect of nanoscale grain size on the lower phase transition temperature in the VO2film was discussed.