热致变色薄膜材料的制备与辐射特性

发布时间：2018-06-06 12:38

本文选题：热致变色 + 薄膜　；参考：《南京理工大学》2014年硕士论文

【摘要】：随着微小航天器的发展,其对器件轻量化的要求越来越高,传统的MEMS百叶窗等热控器件因其体积大、质量重、结构复杂等特点而难以应用于微小卫星。钙钛矿锰氧化物是一种热致变色可变发射率材料,可以根据自身的温度水平,自动调节辐射特性,起到主动智能控温的作用,在航天领域有很大应用前景。本文采用磁控溅射法在掺亿氧化锆(YSZ)单晶基片、硅(Si)单晶基片和石英玻璃表面制备钙钛矿锰氧化物La1-xAxMno3(A=Ca, Sr)热致变色薄膜,溅射过程中调节溅射气压、氧分压、溅射时间等参数,分析薄膜材料的组份、基片和溅射条件等因素对薄膜沉积速率的影响。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、原子力显微镜(AFM)、和能谱仪(EDS)对样品的晶体结构、表面形貌、粗糙度、元素组成等物性进行测量,分析基片、溅射条件和薄膜材料组份对样品上述物性的影响。XRD分析结果显示在YSZ、Si基片和石英玻璃表面溅射的薄膜样品都是单相钙钛矿结构,SEM测量显示：当薄膜厚度较小时,表面光滑、平整、致密；当厚度较大时,表面出现凹槽和粘附的颗粒,粗糙度变大。AFM的测量结果与SEM测量结果吻合。使用傅里叶红外光谱仪在不同温度下测量薄膜样品的光谱反射率,进行积分计算获得薄膜样品在不同温度下的发射率,分析基片、溅射条件和薄膜材料组份等因素对样品发射率的影响。结果表明, YSZ和Si单晶基片上的薄膜样品,氧分压和溅射压力对发射率变化有影响；当膜厚低于“集肤深度"0.9μm时,发射率几乎不随温度变化,当膜厚高于0.9gm时,发射率随温度升高而增大。YSZ基片上的La0.7Ca0.3MnO3、La0.8Sr0.2MnO3\La0.7Ca0.165Sr0.135MnO3薄膜样品的发射率曲线接近,变化范围较小,La0.7Sr0.3MnO3发射率变化范围较大；Si基片上的La0.8Sr0.2MnO3.La0.7Ca0.3MnO3和La0.7Sr0.3MnO3薄膜样品的发射率变化范围依次减小。直接在石英玻璃上沉积La0.7Sr0.3MnO3薄膜样品的发射率变化不大。选用Ag或A1作为过渡层,发射率随温度升高而增大,其中选用A1过程层时,发射率变化范围随压力升高而变大,同温度下发射率随压力升高而减小。
[Abstract]:With the development of small spacecraft, the requirement of lightweight devices becomes more and more high. Traditional MEMS blinds and other thermal control devices are difficult to be used in micro satellites because of their large volume, heavy mass and complex structure. Perovskite manganese oxide is a thermochromic variable emissivity material which can automatically adjust the radiation characteristics according to its temperature level and play an active and intelligent role in temperature control. In this paper, perovskite manganese oxide La1-xAxMNO _ 3 Aca-CaCa (Sr) thin films were deposited on monocrystalline substrates, silicon monocrystalline substrates and quartz glass by magnetron sputtering. The sputtering pressure, oxygen partial pressure and sputtering time were adjusted during sputtering. The effects of composition, substrate and sputtering conditions on the deposition rate of thin films were analyzed. The crystal structure, surface morphology, roughness and elemental composition of the samples were measured by X-ray diffractometer, scanning electron microscope (SEM), atomic force microscope (AFM) and energy dispersive spectroscopy (EDS). The effect of sputtering conditions and the composition of thin film materials on the above mentioned physical properties. XRD analysis results show that the films sputtering on YSZ Si substrates and quartz glass surfaces are single-phase perovskite structure SEM measurements show that when the film thickness is small, the surface is smooth. When the thickness is larger, the groove and the adhesion particles appear on the surface, and the measurement results of the roughness become larger. The measured results are in good agreement with the results of SEM. The spectral reflectance of thin film samples was measured by Fourier infrared spectrometer at different temperatures. The emissivity of thin film samples at different temperatures was obtained by integral calculation, and the substrate was analyzed. The effects of sputtering conditions and composition of thin films on the emissivity of the samples. The results show that the oxygen partial pressure and sputtering pressure affect the emissivity of the films on YSZ and Si single crystal substrates, and when the film thickness is lower than 0.9 渭 m, the emissivity almost does not change with temperature, and when the film thickness is higher than 0.9gm, the emissivity of the films is higher than that of 0.9gm. The emissivity of La0.7Ca0.3MnO3-La0.8Sr0.2MnO3\ La0.7Ca0.165Sr0.135MnO3 films on YSZ substrates increases with the increase of temperature. The emissivity curve of La0.7Sr0.2MnO3 / La0.7Ca0.165Sr0.135MnO3 films is close to that of La0.7Sr0.3MnO3 films. The range of emissivity of La0.7Sr0.3MnO3 films on Si substrates is larger than that of La0.8Sr0.2MnO3.La0.7Ca0.3MnO3 and La0.7Sr0.3MnO3 films on Si substrates. The emissivity of La0.7Sr0.3MnO3 films deposited directly on quartz glass has little change. The emissivity increases with the increase of temperature when Ag or A1 is selected as the transition layer. The range of emissivity increases with the increase of pressure and decreases with the increase of pressure at the same temperature.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB383.2

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