用于探测的纳米级材料相变特性研究
1.利用溶胶-凝胶法，制备VO2薄膜。在玻璃衬底表面尝试制备VO2薄膜，并适当改变制备条件，对制备的薄膜的结构和性能进行研究，了解制备条件的变化对薄膜性能的影响。
2.利用X射线衍射（XRD）分析薄膜相结构组成并测定相变前后VO2薄膜的红外光透射率，并分析其变化。27681
毕业论文关键词 VO2薄膜 相变 溶胶-凝胶法 XRD 红外透射率
毕业设计说明书外文摘要
Title The properties of phase transition of nanoscale materials for detecting
Abstract
VO2 is the most studied one of many vanadium oxide, not only because of VO2’s significant nature of the mutation, the more important is that the phase transition temperature is about 68 ℃, closest to room temperature, which has a greatly practical potential. The change of VO2 between low temperature semiconductor states and high temperature metallic state is a fast reversible phase change. When the temperature reaches the phase transition point, the structure and properties of VO2 material occur simultaneously mutates in nanosecond time range ,the crystals changes from monoclinic crystals to tetragonal transition, the resistance mutates, and infrared spectral characteristics of high transmittance changes to high reflection. So it can be widely used in thermal switches, temperature sensors, information storage, and large areas of glass curtain wall and other fields. Based on this, the study of this issue from the following two aspects:
1. The using of sol - gel method for preparation VO2 film. Try to prepare VO2 film on glass substrate surface, and change the preparation conditions appropriately, to provide the appropriate parameters to quality VO2 film.
2. The using of X-ray diffraction (XRD) analysis of the composition of the thin film phase structure .And determination of the infrared light transmittance around phase transition of VO2 films, and analyzing the changes.
Keywords VO2 films phase transition sol-gel method XRD the infrared light transmittance
目 次
1 绪论2
1.1 引言2
1.2 VO2结构及相变机理2
1.3 VO2薄膜的制备方法5
1.4 影响相变性能的因素8
1.5 VO2薄膜的应用11
1.6 本论文主要内容11
2 VO2薄膜的制备13
2.1 引言13
2.2溶胶-凝胶法13
2.3旋涂技术14
2.4薄膜的制备15
2.5制备条件的不同对薄膜团簇的影响18
2.6小结20
3 VO2薄膜红外特性的测试21
3.1引言21
3.2 VO2薄膜的XRD检测21
3.3 VO2薄膜的红外特性检测23
3.4 小结29
结论30
致谢 31
参考文献32
1绪论
1.1 引言
上世纪五、吹冰十年代，研究者们发现了钒的一些低价氧化物具有随温度的改变而在半导体态和金属态之间转化，这一现象被称为金属-半导体相变（MST）。伴随着材料的相变，其电光学特性发生着显著的变化。而这其中，由于VO2的相变温度在68℃（340K），相对接近室温，且光学特性的改变集中在可见光和近红外区域，因此它是一种极具实用价值的钒氧化物，受到较大关注。二氧化钒材料在低温半导体态和高温金属态之间的转换是一种快速并且可逆的变换[2]，当升高温度直至相变点时，VO2的物理、化学性能和微观结构会在极短的时间内发生突变，其晶格结构会由畸变的金红石结构（单斜金红石结构）转变为四方金红石结构[3]，其电导率的变化可达105数量级，而对于红外波段入射光，二氧化钒材料会由高透射特性变为高反射特性。而当温度下降并且低于降温相变点时，二氧化钒材料晶格结构又会恢复为单斜金红石结构，同时，电光学特性也会恢复相变前的状态。