摘要
将Ta2O5与V2O5均匀混合,压制成溅射靶,用离子束增强沉积方法在二氧化硅衬底上沉积掺Ta氧化钒薄膜。在氮气中适当退火,形成掺杂二氧化钒多晶薄膜。X射线衍射结果显示,薄膜具有单一的(002)取向。XPS测试表明,膜中V为+4价,Ta以替位方式存在。温度-电阻率测试表明,薄膜具有明显的相变行为,原子比为3%的Ta掺杂后,二氧化钒多晶薄膜相变温度降低到约48℃。Ta原子的半径大于V原子的半径,Ta的掺入在薄膜中引入了张应力;5价Ta替代4价V,在d轨道中引入多余电子,产生施主能级,这些是掺钽二氧化钒多晶薄膜相变温度降低的原因。
The vanadium oxide film was deposited on the SiO2 substrate by modified Ion Beam Enhanced Deposition （IBED） method. The V2O5 and Ta2O5 mixing powders were pressed as the sputtering target. After annealing in N2 the polycrystalline IBED VO2 film doped with tantalum was obtained. The Ta doped film was orientated only to （002） of VO2 structure measured by X-ray Diffraction （XRD）. The valence of vanadium and doped Ta in the film was ＋4 confirmed by X Ray Photoelectron Spectroscopy（XPS）, it means that the doped Ta was substitution atom. The results of resistance-temperature testing showed that the phase transition temperature was decreased from 68℃ to 48℃. The reasons would be as following： With the atomic size of Ta was larger than the size of vanadium atom Ta doping would induce a tension stress into the film; When Ta^5＋ replaced V4＋ it introduced excrescent electrons in the d valence shell, then make the gap of d energy band to decreasing.
出处
《红外技术》
CSCD
北大核心
2010年第3期173-176,共4页
Infrared Technology
基金
国家自然科学基金资助项目(编号:60277019)
关键词
二氧化钒薄膜
Ta掺杂
离子束增强沉积
VO2 film, Ta doping, ion beam enhanced deposition, phase transition
