Ba掺杂热致变色薄膜制备及其热辐射特性研究
毕业论文关键词 可变发射率，Ba掺杂锰氧化物，光谱反射率，热致变色薄膜
Title Preparation for Ba doped thermalchromic thin film and
investigation on its thermal radiation Properties
Abstract
Due to the development of micro-spacecraft, there is an increasing demand for
micro-spacecraft to reduce the weight of thermal control devices. Traditional thermal
control devices all have some drawbacks. For example, Traditional shutter is too
bulky and heavy and MEMS shutter is inconvenient for preparation. The voltage
needed to drive the electrostatic thermal switch is too high. There is also a
problem for electrochromic thermal control devices which they would undergo the
degradation of electrochromic. These problems make them inappropriate be applied in
micro-spacecraft which have an extremely strict standard on its weight control. These
doped perovskite-type manganese oxides have many unique physical properties. For
example, the material shows an increased emissivity upon heating based on the
properties of metal-insulator transition. Namely, they show a metallic behavior with
low emissivity at low temperature, on the contrary, at high temperature they show high
emissivity which suggests insulating nature. The radiation surface fabricated by these
materials can automatically adjust its infrared emissivity to high or low in response to
variation of thermal load and environment temperature without any electrical and
mechanical parts, which makes micro-spacecraft realize the smart thermal control.
From the perspective of light-weight demand for the thermal control of
micro-spacecraft, this thesis investigates the thermal radiation property of the
thermalchromic thin films based on Ba doped perovskite-type manganese oxides and
compares it with Sr doped perovskite-type manganese oxides thin film spurted on the
YSZ substrate. The following main results were obtained: Firstly, the present studies of
thermalchromic material are briefly introduced. Secondly, the preparations of target
material are mainly introduced and the methods which the predecessors used to prepare
bulk ceramic materials are summarized. The fabrication process of solid state reaction
method for the target material is also introduced. Thirdly, some widely used methods in
producing thin films are presented and a detailed introduction of the method we used in
this experiment is given. Lastly, Fourier transform infrared spectrometer is used to
measure the spectral reflectivity under different temperature. And then thermal
emissivity is obtained by integrating the temperature-dependent reflectivity.