钙钛矿锰氧化物La1-xAxMnO3（A=Ca、Sr、Ba等）具有对外界温度变化表现出的金属-绝缘体转变行为，高TCR数值和Tk接近室温的La(Ca,Sr)MnO3多晶材料可用于制备高灵敏、近室温Bolometer等红外探测器件。本课题组制备的LaCaMnO3:Ag0.4材料TCR数值达到28%/K（Tk=271.3K），TCR数值比目前最好结果（TCR=15%/K，Tk=270.5K）增大了近两倍，然而该材料Tk数值远离室温（300K），限制了其应用。本项目拟采用溶胶－凝胶法，通过Ag掺杂改善TCR、Ca和Sr共掺优化Tk，同时，通过XRD、R-T、SEM、M-T、XPS、EPMA、RBS和Raman等研究Ag掺杂与微结构调控和TCR、Tk数值之间的关联机理，为制备近室温高TCR数值的La1-xAxMnO3和其它多元材料提供理论基础。

Perovskite manganites with general formula La1-xAxMnO3 (A=Ca, Sr, Ba, etc.) showed excellent metal to insulator (MI) transition behavior under the variation of temperatures. High TCR (Temperature Coefficient Resistance) and near room temperature Tk (TCR transition temperature) La(Ca,Sr)MnO3 polycrystalline materials can be used to prepare close room temperature bolometer and other infrared detectors. The TCR value of La0.67Ca0.33MnO3:Ag0.4 polycrystalline reached 28% /K (Tk=271.3K) by our previous works, which improved nearly double times compared with the best results (TCR=15% /K,Tk=270.5 K). However, the value of Tk was still far away from the room temperature (300K), which limited its further applications. In this project, we proposed to improve the TCR and Tk values of La(Ca,Sr)MnO3 materials with silver doping and Ca/Sr co-doping by sol-gel methods, respectively. Meanwhile, the co-related mechanism of Ag doping and micro-structural tuning the values of TCR and Tk in La(Ca,Sr)MnO3 materials will be discussed by the results of XRD, R-T, SEM, M-T, XPS, EPMA, RBS and Raman, which can be provided the theoretical foundation to prepare nearly room temperature and high TCR La1-xAxMnO3 or other multielement materials.