用 sol‐gel 法制备 SmFe1－ y Sry O3（y ＝0，0．1，0．2，0．3，0．4，0．5，0．6）粉体．XRD 图谱表明 SmFe1－ y Sry O3为正交钙钛矿结构，粉体的晶胞体积和晶粒尺寸均随 Sr2＋含量的增大而增大．用 SmFe1－ y Sry O3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 SmFe0．7 Sr0．3 O3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 SmFeO3元件的10．80倍． SmFe0．7 Sr0．3 O3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28 s 和83 s ．%SmFe1 - y Sr y O3 (y = 0 ,0 .1 ,0 .2 ,0 .3 ,0 .4 ,0 .5 ,0 .6) powders with an orthogonal perovs‐kite 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 ex‐perimental 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 .7 Sr0 .3 O3 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 .7 Sr0 .3 O3 is 26 .14 at the best working temperature (240 ℃ ) ,is about 10 .80 times as high as that of SmFeO3 .Moreo‐ver ,response‐recovery time is 28 s and 83 s ,respectively .
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