摘要  随着工业生产的飞速发展，环境问题日趋恶化，已严重影响到人类的生活。煤、石油、天然气的大量使用，以及工业化生产过程中所排放的废气、汽车尾气等释放的有毒有害气体，加剧了环境的污染，破坏生态平衡。环境的恶化促进了气敏传感器的发展，半导体氧化物气敏材料越来越受到人们的关注。钙钛矿(ABO3)型氧化物BiFeO3因其具有很好的多铁性而被广泛研究，但对其气敏性的研究却相当于空白。因此，本论文对BiFeO3的气敏性进行了深入研究，发现该材料具有极好的气敏性。86313

    采用酒石酸溶胶凝胶法制备Sr掺杂的BiFeO3纳米颗粒，将前驱体分别在不同条件下烧结一定时间得到BiFeO3粉体。利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对样品的结构、形态和成分进行分析。将Sr掺杂的BiFeO3纳米颗粒制作成气敏元件，测试对酒精、丙酮和苯等多种气体的气敏性。结果显示，BiFeO3气敏元件的最佳工作温度为240℃，在该温度下，对酒精和丙酮具有较高的灵敏度。Sr掺杂对BiFeO3的气敏性有很大提高，并且工作温度大大降低，但掺杂浓度过高则不能明显提高其气敏性能。可知BiFeO3对一些有机气体（如酒精和丙酮）具有灵敏度高、检测下限低、响应恢复时间快和选择性好等特点。BiFeO3的优异性质对于气敏材料研究意义重大，本文为BiFeO3在环境监测检测的领域中提供了新的应用前景。 

毕业论文关键词：BiFeO3；溶胶凝胶；气敏；掺杂

Abstract   With the rapid development of industrial production, worsening environmental problems, it has seriously affected the human life。 Extensive use of poisonous gases of coal, oil, gas, and industrial production process of exhaust emissions, car exhaust  toxic gases, increasing the environmental pollution, destruction of ecological balance。 Deterioration of the environment to promote the development of gas sensors, semiconductor oxide sensitive materials attracts more and more people's attention。 Perovskite (ABO3) type oxide BiFeO3 because of its good multiferroic properties has been extensively studied, but its gas sensitivity study is equivalent to a blank。 Thus, the gas sensitivity BiFeO3 is conducted intensively study in this thesis and found that the material has excellent gas sensitivity。

    The nanoparticles of Sr-doped BiFeO3 were fabricated by tartaric acid sol-gel method, sintering the precursor for a period of time in different conditions and get the BiFeO3 powder。 The structure, morphology and composition of sample are analysized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM)。 The production of Sr-doped BiFeO3 nanoparticles are made as a gas sensor and tested in variety of gases such as alcohol, acetone and benzene gas sensitivity。 The results showed that the optimum operating temperature of BiFeO3 gas sensor is 240℃, at this temperature, alcohol and acetone with high sensitivity。 Gas sensitivity of Sr doping BiFeO3 has greatly improved, and the operating temperature is greatly reduced, but the doping concentration is too high to significantly increase its gas sensing performance。 Some organic gases (such as alcohol and acetone) with high sensitivity, low detection limit, response and recovery time is fast and good selectivity of BiFeO3。 BiFeO3 nanoparticles excellent properties is a great significance for sensitive material research, the paper offers a new prospects for BiFeO3 in the field of environmental monitoring for detection。

Key words: BiFeO3; sol-gel; gas sensing; doping

目  录

摘  要V

Abstract。。VI第一章 绪论。。1

  1。1  引言。1

  1。2  BiFeO3材料研究进展。。1