【摘要】 以La₂O₃、Cr（NO₃）₃·9H₂O、St（NO₃）₂、Mn（NO₃）₂和柠檬酸为原料,用溶胶-凝胶法制备了La_0.75Sr_0.25Cr_0.5Mn_0.5O₃粉体。使用DTA、XRD、SEM、FT-IR等对粉体及中间体进行了表征。结果表明,用此法制备的前驱体,经700℃焙烧2h即可制得粒度均匀的晶体,其平均粒径为4.87nm。以制得的粉体为气敏材料制备了管状NO₂气体传感器,并测试了传感器的性能。结果表明,La_0.75Sr_0.25Cr_0.5Mn_0.5O₃材料对NO₂具有良好的敏感性能。在一定温度范围内,随着NO₂浓度的升高,传感器电动势信号逐渐增大。在测试温度范围内,电动势与NO₂浓度之间呈良好的线性关系。更多还原

【Abstract】 Lao_0.75Sr_0.25Cr_0.5Mn_0.5O₃ powders were prepared by sol-gel method using La₂O₃,Cr（NO₃）₃·9H₂O,Sr（NO₃）₂,Mn（NO₃）₂ and citric acid as raw materials.The powders and dry gel were characterized by means of DTA,XRD,SEM and FT-IR.The results show that the powders exhibited an homogeneous phase with particle size of 4.87nm after calcined at 700℃for 2h.The prepared powders were used as the gas sensing materials for the fabrication of tubular NO₂ sensor,and sensing performances is tested.The results show that the La_0.75Sr_0.25Cr_0.5Mn_0.5O₃ exhibits high sensitivity to NO₂ gas.The relationship between EMF and NO₂ concentration is linear.更多还原