摘要采用固相反应法制备热致变色靶材,通过磁控溅射法在单晶硅基片上制备三种不同厚度的热致变色薄膜。用扫描电子显微镜(SEM)对薄膜的表面形貌、粗糙度进行测量,分析薄膜厚度对表面形貌的影响。结果显示薄膜厚度较小时,表面致密、光滑;厚度较大时,粗糙度变大。用傅里叶红外光谱仪测出薄膜的红外光谱反射率,计算得出薄膜在不同温度时的发射率,分析薄膜厚度对其辐射特性的影响。结果显示,在低温区域,薄膜呈现铁磁金属态,发射率低;高温区域,呈现顺磁绝缘态,发射率高。且在厚度低于一定值时,由于基片的影响,发射率变化范围很小;高于该值后,发射率变化范围不随厚度改变而有明显变化。84188
毕业论文关键词 热致变色薄膜 磁控溅射 反射率 可变发射率
毕业设计说明书外文摘要
Title Radiative properties of thermochromic film prepared by magnetron sputtering
Abstract The thermochromic target was prepared by conventional solid state reaction。Three different thicknesses La0。7Ca0。25K0。05MnO3 films was prepared by magnetron sputtering system。Using the scanning electron microscope (SEM) to detect the surface morphology and roughness of the films, analyze the impact of thickness on the surface morphology。The results show that thin film is smooth and dense,when its thickness is small。While its surface become rough,when the thickness become large。Reflectivity spectra of thin film samples in different temperature are measured using the Fourier transform infrared spectroscopy,and obtained the film's emissivity by calculation。Analyze the effect of thickness on thin film radiation characteristics。 The results show that film shows the metallic state and its emissivity is low when the temperature is low,while film shows the insulating characteristics and its emissivity is high when temperature is high。Due to the influence of the substrate,the emissivity variation range is small when the thickness is less than a certain value。While the thickness is higher than this value,the emissivity variation range regardless of the thickness。
Keywords Thermochromic films Magnetron sputtering Reflectivity Variable emissivity
目 次
1 引言 1
2 样品的制备技术 3
2。1 块状样品的制备方法 3
2。2 热致变色薄膜样品的制备方法 4
3 磁控溅射法制备热致变色薄膜 6
3。1 磁控溅射系统的原理及装置6
3。2 热致变色薄膜的制备 7
4 La0。7Ca0。25K0。05MnO3薄膜的表面形貌及辐射特性分析13
4。1 La0。7Ca0。25K0。05MnO3薄膜的表面形貌分析13
4。2 热辐射性能测试方法 14
4。3 厚度对热致变色薄膜辐射特性的影响 15
结论 19
致谢 21
参考文献22
1 引言
航天器热控制技术主要是通过控制各分系统温度,从而使整体达到要求的性能,即保证航天器在空间环境中能在适合的温度区间内工作。
航天技术的迅速发展使得航天器热控制技术也得到了很大提升,而且种类也变得越来越多,为了适应于各种工作情况。从当前的航天器热控技术的发展状况来看,航天器热控技术基本可以分为主动热控制技术以及被动热控制技术两种。被动热控制技术相对于主动热控技术来说应用得更多一些,被动热控技术经过改善航天器内部的结构及与外界热交换状况,以达到使航天器各部件能在适当的温度下工作的目的。被动热控技术也可以通过使用各种热控器件(如热控涂层)来避免航天器与外界宇宙之间的不可控制热交换,尽可能降低外界宇宙对航天器正常工作产生影响。