SmFe_(1-y)Sr_yO_3的制备及其气敏性能

Study on preparation and gas sensing properties of SmFe_(1-y)Sr_yO_3 nanopowders

用sol-gel法制备SmFe_(1-y)Sr_yO_3(y=0,0.1,0.2,0.3,0.4,0.5,0.6)粉体.XRD图谱表明SmFe_(1-y)Sr_yO_3为正交钙钛矿结构,粉体的晶胞体积和晶粒尺寸均随Sr^(2+)含量的增大而增大.用SmFe_(1-y)Sr_yO_3纳米粉体制备成气敏元件,测试了其对乙醇气体的气敏特性.结果表明,在同等条件下,以SmFe_(0.7)Sr_(0.3)O_3元件对乙醇的气敏性能最优,在工作温度为240℃时对体积分数为1×10^(-4)的乙醇的灵敏度达到26.14,是SmFeO_3元件的10.80倍.SmFe_(0.7)Sr_(0.3)O_3元件同时还表现出较好的选择性、响应-恢复特性与稳定性,工作温度为240℃时的响应时间和恢复时间分别为28s和83s.

SmFe1-ySryO3（y=0,0.1,0.2,0.3,0.4,0.5,0.6）powders with an orthogonal perovskite structure were synthesized by using the sol-gel method.The samples were characterized by XRD and TEM respectively and the gas-sensing properties were studied to ethanol gas.The experimental results show that,their cell volume and grain size increase with increase of Sr^2＋content y.In all the gas sensors,the gas sensor based on SmFe0.7Sr0.3O3 material shows higher resistance sensitivity and better selectivity to ethanol gas under the same condition.To 1×10^-4 ethanol（volume fraction）,the maximum resistance sensitivity of SmFe0.7Sr0.3O3 is 26.14 at the best working temperature（240 ℃）,is about 10.80 times as high as that of SmFeO3.Moreover,response-recovery time is 28 sand 83s,respectively.