化学共沉淀法低温合成La_(0.5)Sr_(0.5)CoO_3多晶  

La_(0.5)Sr_(0.5)CoO_3 Polycrystals Synthesized at Low Temperature by Chemical Coprecipitation Method

作　　者：杨有利[1] 伍光凤[1] 严磊[2] 张鹏翔[2] 

机构地区：[1]重庆工学院材料科学与工程学院,重庆400050 [2]昆明理工大学光电子新材料研究所,云南昆明650051

出　　处：《热加工工艺》2007年第16期16-18,共3页Hot Working Technology

基　　金：导电钨钛矿薄膜制备973子课题(6294-20030003)

摘　　要：分别以草酸铵和碳酸氢铵为沉淀剂,用化学共沉淀法制备了La0.5Sr0.5CoO3（LSCO）样品。用XRD分析了物相、结构与晶粒大小,用电阻-温度系统绘制了电阻-温度曲线。结果表明,1150℃烧结,用草酸铵和碳酸氢铵法制备的La0.5Sr0.5CoO3均为单一立方钙钛矿多晶。晶体参数分别为0.384、0.383nm。晶粒垂直于（110）面的尺寸分别为37nm与32.8nm。草酸铵作沉淀剂的烧结温度比碳酸氢铵的低,比固相烧结反应法的低至少150℃。La0.5Sr0.5CoO3均为半导体,有良好的电阻-温度关系,190-280时两种沉淀剂法制备的LSCO的平均激活能分别是30、150eV。Taking ammonium oxalate and mmonium hydrogen bicarbonate as precipitant,the samples of La0.5Sr0.5CoO3 were prepared by chemical coprecipitation methods. The phase, structure and grain size were analyzed by XRD and resistance-temperature curve was drawn by system. The results show that the samples of La0.5Sr0.5CoO3prepared by two methods are single cubic calcium titanium phase. Lattice is 0.384 nm and 0.383 nm, respectively.Grain is perpendicular to face （110） and its size is 37 nm and 32.8 nm, respectively . The sintering temperature of ammonium oxalate is lower than that of mmonium hydrogen bicarbonate, at least 150℃ lower than that of solid state reaction. The samples of La0.5Sr0.5CoO3 are semiconductor and have good resistance-temperature relation. The activation energy of La0.5Sr0.5CoO3 prepared by ammonium oxalate and mmonium hydrogen bicarbonate is 30eV and 150eV from 190 K to 280 K, respectively.

关 键 词：La0.5Sr0.5CoO3 化学共沉淀法 草酸铵 碳酸氢铵 

分 类 号：TB331[一般工业技术—材料科学与工程] TG146.32[金属学及工艺—金属材料]