溶胶-凝胶法制备La_(0.67)Sr_(0.33)MnO_3:Ag_x多晶材料及其性能  

Preparation and Properties of La_(0.67)Sr_(0.33)MnO_3:Ag_x Polycrystalline by Sol-gel Method

作　　者：殷学鹏[1] 晏益志[1] 陈清明[1] 段云彪[1] 刘翔[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093

出　　处：《热加工工艺》2014年第20期84-87,共4页Hot Working Technology

基　　金：国家自然科学基金资助项目(50974066);国家自然科学基金项目资助(61367008);云南省自然科学基金资助项目(2009ZC013M)

摘　　要：采用溶胶-凝胶法制备La0.67Sr0.33Mn O3∶Agx(LSMO∶Agx,x为摩尔百分比,x=0,0.04,0.08,0.10,0.20)多晶材料。通过XRD和R-T对LSMO∶Agx多晶材料的结构和性能进行分析。结果表明:在950、1050℃烧结的样品具有良好的单相结构。1050℃烧结时,Ag进入晶格替换A位La3+或Sr2+,使晶胞发生畸变、晶胞体积增大。Ag掺杂明显降低了样品电阻率,950℃烧结的Ag掺杂样品的电阻率降低了近两个数量级。提高烧结温度有助于改善LSMO材料的Tp和TCR。烧结温度由950℃变化到1050℃时,x=0样品的Tp增加了将近10 K,x=0.04样品的TCR从0.09%K-1上升到0.50%K-1。Ag掺杂能有效改善LSMO材料的电学性能。La0.67Sr0.33MnO3：Agx（x=0, 0.04, 0.08, 0.10 and 0.20） polycrystalline was prepared by sol-gel method. The microstructure and performance of La0.67Sr0.33MnO3：Agx samples were investigated by XRD and R-T. The results show that, all the samples with single phase perovskite structure are obtained. With the sample of sintering temperature at 1050℃, Ag is partially substitute for A site of La3＋ or Sr2＋, which can result in a small lattice distortion and cell volume increasing. The resistivity ofLSMO ： Agx sample reduces significantly by Ag doping. In addition, the resistivity of Ag doping samples sintered at 950℃ is lower 2 orders than pure sample. The value of Tp and TCR are significantly improved with increasing sintering temperature. Tp of the pure sample improve approximately 10 K, and TCR of Ag doping x=0.04 samples rises from 0.09%K-1 to 0.50 %K-1. The electrical properties ofLSMO polycrystalline are improved by Ag doping.

关 键 词：La0.67Sr0.33MnO3:Agx(LSMO:Agx) 溶胶-凝胶法 AG掺杂 金属绝缘体转变温度(Tp) 电阻温度系数(TCR) 

分 类 号：TG113.2[金属学及工艺—物理冶金]