退火温度对SmFeO_3微结构、电性能与乙醇气敏的影响  

Effects of Annealing Temperature on Microstructure,Electrical and Gas-sensing Properties for SmFeO_3

作　　者：赵玛[1] 彭辉[1] 方少明[1] 韩周祥[1] 胡季帆[1] 魏剑英[1] 

机构地区：[1]郑州轻工业学院材料与化学工程学院,河南郑州450002

出　　处：《稀土》2008年第3期37-40,共4页Chinese Rare Earths

基　　金：国家自然科学基金项目资助(59772040)

摘　　要：采用溶胶-凝胶法合成了SmFeO3前驱体,并在不同温度条件下退火制备了具有单一正交钙钛矿结构的系列纳米粉体材料,利用该粉体做成了气敏元件,研究了退火温度对SmFeO3晶体结构、微结构、电性能及酒敏特性的影响,结果表明,随退火温度的增高,SmFeO3的晶胞体积减小,平均晶粒尺寸变大,元件的电导也随之增大。随退火温度从600℃增加到850℃,SmFeO3元件的最佳工作温度和气敏灵敏度增高,同时对应的气敏响应-恢复时间也变短;若退火温度进一步增高到950℃,气敏灵敏度和最佳工作温度出现下降趋势,同时对应的气敏响应-恢复时间变长。850℃退火的样品显示出最高的气敏灵敏度,对300×10-6乙醇的最大灵敏度高达51.03,气敏的响应-恢复时间短且选择性高。同时对SmFeO3元件的电导、气敏灵敏度、最佳工作温度随材料退火温度的变化规律给予了解释。The SmFeO3 samples were prepared by a sol- gel technique,followed by annealing at different temperatures. The influences of annealing temperature upon the crystal cell volume, microstructure, electrical and gas - sensing properties for SmFeO3 were investigated. With increasing annealing temperatures, the volume of unit cell reduces but the average grain size increases. With in- creasing annealing temperature from 600℃ to 850℃, the optimal working temperature and sensing sensitivity increases, accompany- ing shortening of response recovery time. With further increasing the annealing temperature to 950℃, there are decreases of the optimal working temperature and sensing sensitivity, accompanying the prolonging of the response - recovery time. The results indicate that 850℃ is the optimal annealing temperature for gas sensing of SmFeO3, it shows the highest sensitivity S = 51.03 to 300 × 10^-6 ethanol with best response - recovery time and selectivity. Meanwhile, the influence mechanisms of annealing temperatures upon conductivity, optimal working temperature and sensing sensitivity for SmFeO3 were studied.

关 键 词：钙钛矿 退火温度 电性能 气敏性 

分 类 号：TB383[一般工业技术—材料科学与工程] TN304[电子电信—物理电子学]