摘要
采用Sol-gel法制备出气敏材料La0.68Pb0.32FeO3纳米粉体.该粉体材料具有正交钙钛矿结构,晶胞参数a=0.555 62 nm,b=0.559 65 nm,c=0.781 85 nm,晶胞体积v=0.243 1 nm3,平均粒径约为20 nm.用该粉体制成气敏元件,并测试了该粉体材料在乙醇、丙酮和汽油中的气敏特性,测试结果表明:相比空气而言, 在乙醇气氛中的La0.68Pb0.32FeO3电导值升高,呈现出n-型半导体载流子的导电特性;在丙酮和汽油气氛中的La0.68Pb0.32FeO3的电导值降低,呈现出p-型半导体载流子的导电特性.该材料对乙醇具有极高的气敏灵敏性,在0.01%的乙醇气氛中,灵敏度可达51;在0.1%的乙醇气氛中,灵敏度高达522.最佳工作温度区间在180℃～220℃.La0.68Pb0.32FeO3对丙酮和汽油也具有一定的灵敏性,在0.05%丙酮气氛中的灵敏度为30,最佳工作温度区间在220℃～260℃.在0.1%汽油气氛中的灵敏度为5.0.La0.68Pb0.32FeO3纳米粉体具有电子与空穴复合导电机制.
The sample La0.68Pb0.32FeO3 was prepared by using a sol-gel method. The X-ray diffraction patterns indicated that sample La0.68Pb0.32FeO3 has an othogonal perovskite structure. The lattice parameter a, b, c, and cell-volume nu are 0.555 62 nm, 0.559 65 nm, 0.781 85 nm, and 0.243 1 nm(3), respectively. The grain size is about 20nm. The gas-sensing properties have been studied in alcohol, acetone and gasoline. The experimental results revealed that the sample La0.68Pb0.32FeO3 shows a n-type semiconductor in alcohol, but a p-type semiconductor in acetone and gasoline. Compared with the conductivity of the sample La0.68Pb0.32FeO3 in air, that of the sample La0.68Pb0.32FeO3 increases in alcohol, but decreases in acetone and gasoline. Lao.68PbO.32FeO3 possesses a high sensitivity to alcohol. The sensitivity in 0.01% and 0.1% alcohol at T=200degreesC for La0.68Pb0.32FeO3 is 51 and 522, respectively. The best operating temperature range is 180degreesCsimilar to220degreesC in alcohol. The sensitivity in 0.05% acetone at T=240degreesC for La0.68Pb0.32FeO3 is 30. The best operating temperature range is 220degreesCsimilar to260degreesC in acetone. We suggest that the La0.68Pb0.32FeO3 has electron/hole complek conductivity mechanisms .
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2004年第3期293-296,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金资助(59772040)
