合成工艺对镧锶锰氧陶瓷材料性能的影响研究

Study on the Effect of Synthesis Technology on Properties of Lanthanum Strontium Manganese Oxide Ceramics

采用高温固相合成工艺制备了La_(0.8)Sr_(0.2)MnO_(3)粉末,研究了不同热处理温度对粉末物理性能的影响,结果表明,1100℃热处理条件下合成的粉末除了La_(0.8)Sr_(0.2)MnO_(3)晶相之外,还含有未参与反应的La_(2)O_(3)以及中间产物La_(2)SrO_(x)相,当热处理温度分别为1200℃和1300℃时,合成的样品为单相钙钛矿(ABO_(3))结构。当温度从1100℃升高至1200℃时,粉末松装密度增大,流动性变好,当温度继续升高至1300℃时,粉末流动性变差,不利于致密陶瓷材料的制备,综合考虑选择1200℃为适宜的热处理温度。采用压制烧结工艺制备了La_(0.8)Sr_(0.2)MnO_(3)陶瓷块体材料,对其发射率调控性能进行了测试,样品表现出良好的发射率调控性能。

La_(0.8)Sr_(0.2)MnO_(3)powder was prepared by high temperature solid phase synthesis process.The influence of different heat treatment temperatures on the physical properties of the powder was studied.The results show that the powder synthesized by heat treatment at 1100℃is not only has the crystal phase of La_(0.8)Sr_(0.2)MnO_(3),but also has La 2O 3 and the intermediate La 2SrO x phase.When the heat treatment temperature is 1200℃and 1300℃,respectively,the synthesized sample has a single-phase perovskite(ABO 3)structure.When the temperature rises from 1100℃to 1200℃,the powder loose density increases and the fluidity becomes better.When the temperature continues to rise to 1300℃,the powder fluidity becomes worse,which is not conducive to the preparation of dense ceramic materials.The optimum heat treatment temperature is 1200℃.La_(0.8)Sr_(0.2)MnO_(3)ceramic block material was prepared by pressing sintering process.Its emissivity regulation performance was tested.The sample shows good emissivity control performance.