La_(0.67)Sr_(0.33)MnO_3中Ag-Ti的掺杂效应  

Doping effect of Ag-Ti in La_(0.67)Sr_(0.33)MnO_3

作　　者：王军华[1] 黄宝歆[1] 原晓波[2] 王成建[2] 刘宜华[2] 梅良模[2] 

机构地区：[1]潍坊学院物理系,潍坊261061 [2]山东大学物理与微电子学院和晶体材料国家重点实验室,济南250100

出　　处：《功能材料与器件学报》2007年第2期181-184,共4页Journal of Functional Materials and Devices

基　　金：国家重点基础研究专项经费资助项目(No.G1998061310);潍坊学院自然科学基金(No.2005Z02).

摘　　要：将La0.67Sr0.33MnO3(LSMO)、Ag2O及TiO2粉混合经高温烧结后制备了钙钛矿相/xAg两相复合体系(x是Ag与钙钛矿材料的物质的量比),系统地研究了Ag-Ti的共掺杂对LSMO电性和磁电阻效应的影响。0.07摩尔比Ti4+离子的B位掺杂使LSMO的居里温度降至室温。Ag的掺入对TC影响不大,TP逐渐升高。由于钙钛矿颗粒属性的改善和金属导电通道的出现,材料的电阻率明显下降。Ag掺杂使室温磁电阻得到显著增强,室温下从x=0.30样品中得到最大的磁电阻,约为32%,是La0.67Sr0.33MnO3样品的8倍,La0.67Sr0.33Mn0.93Ti0.07O3样品的1.6倍。The composite of perovskite/xAg （x is the nominal molar ratio of Ag） was prepared by calcining the mixture of La0.67Sr0.33MnO3 （LSMO）, TiO2 and Ag2O powders. The effects of Ag -Ti addition in LSMO tent, Tc of the samples changes slightly while Tp increases gradually. The resistivity decreases remarkably due to better crystallization of the pervoskite grains and metal conduction channels provided by Ag addition. The magnetoresistance at room temperature is remarkably enhanced by Ag addition. A maximum MR ratio of 32 % at room temperature is obtained for the samples with x = 0.30, which is approximately 8 times and 1.6 times as large as that for La0.67Sr0.33MnO3 and La0.67Sr0.33Mn0.93Ti0.07O3, respectively.

关 键 词：钙钛矿锰氧化物 Ag掺杂的锰氧化物 两相复合体系 室温磁电阻 

分 类 号：O482[理学—固体物理]