退火温度对NdFeO_3微结构及酒敏性能的影响

Effects of annealing temperature on the microstructure and ethanol-sensing properties of NdFeO_3

采用sol-gel法制备了具有单一斜方钙钛矿结构的NdFeO3样品,研究了退火温度对NdFeO3样品的晶格常数、微结构、电性能及酒敏特性的影响。结果表明:随着退火温度的提高,样品的晶胞体积减小,晶粒度变大,利用该样品制成的气敏元件的电导也随之增大。800℃退火的样品显示出最佳酒敏特性,元件对体积分数为5×10–4的乙醇的最大灵敏度高达151.69,不同退火温度的样品均显示出较好的低温(90℃左右)工作特性。

In order to get optimal annealing temperature of the NdFeO3 ethanol-sensing materials, the NdFeO3 samples having single rhomboidal perovskite structure were prepared using the sol-gel method. The influences of annealing temperature on the lattice constant, microstructure, electrical and ethanol-sensing properties for NdFeO3 samples were investigated. The results indicate that with the increase of annealing temperatures, the cell volume reduces; the crystallite of the samples increases; the conductance of the gas sensors fabricated with the samples rises. The samples annealed at 800 ℃ show the best ethanol-sensing property. To 5×10–4 ethanol （volume fraction）, the maximal sensitivity of the gas sensor is 151.69. In addition, the samples annealed at different temperatures appear better sensitivity to ethanol at lower working temperatures （about 90 ℃）.