【作者】 张颖；

【导师】 季惠明；

【作者基本信息】 天津大学 ， 材料学， 2004， 硕士

【摘要】 丙酮气敏传感器在诊断糖尿病、乙型脑炎、脑膜炎以及肉类腐蚀、环境监测等方面有着广泛的应用。本文通过溶胶－凝胶法制备了丙酮气敏材料ZnFe2O4和LaFeO3薄膜，从溶胶的制备、薄膜的形成、丙酮敏感性能等三个方面，对这两种丙酮敏感材料进行了系统的研究。实验中以可溶性无机盐为原料，从溶胶－凝胶法工艺出发，研究了复合氧化物ZnFe2O4溶胶和薄膜的制备过程。结果表明：（1）分别采用柠檬酸和乙酰丙酮作为络合剂，用溶胶－凝胶法都能成功的合成ZnFe2O4薄膜。（2）柠檬酸有利于形成均匀良好的ZnFe2O4溶胶，其络合效果由于乙酰丙酮；pH值对柠檬酸的络合效果有很大影响，pH值增大有助于提高柠檬酸的络合度。（3）烧结温度对于ZnFe2O4薄膜的形态以及晶粒发育有很大的影响，在700℃下烧结可以得到覆盖良好、结构均匀的薄膜。实验研究了复合氧化物ZnFe2O4 和LaFeO3薄膜的电阻－温度特性及其丙酮敏感性能，结果表明：（1）ZnFe2O4 和LaFeO3薄膜电阻随温度升高呈指数下降，表现出明显的半导体特性。（2）ZnFe2O4薄膜为N型半导体，LaFeO3薄膜为P型半导体。（3）ZnFe2O4薄膜对丙酮有一定的敏感性，LaFeO3薄膜对低浓度丙酮的敏感性更好。（4）通过掺杂可以提高LaFeO3薄膜的丙酮敏感性，还可以降低敏感温区。更多还原

【Abstract】 The acetone has very important meaning in diagnosis of diabetes, cephalitis, brain fever, canker of the meat and environmental measurement. ZnFe2O4 and LaFeO3 thin films were prepared by sol-gel method, and the preparation of the sol, the fabrication and sensitivity of the thin films were studied in this experiment.Dissoluble inorganic salts were used as raw materials in this sol-gel method. The result indicated:(1) ZnFe2O4 thin films were successfully fabricated by sol-gel method, with citric acid and acetylacetone as chelating agent. (2) The citric acid has better chelating behavior than acetylacetone on forming homogenous ZnFe2O4 sol and pH plays an important role in the chelate progress of citric acid. (3) The phase formation and grain growth were remarkably affected by the sintering temperature. Sintered at 700℃, a compact, well-coated thin films could be got.The resistance-temperature characteristics and the acetone sensitive properties of the complex oxide ZnFe2O4 and LaFeO3 thin films were also investigated. The conclusions indicated: (1) With the temperature increasing, the resistance of thin films descended by exponent and showed typical semiconductor characteristic. (2) ZnFe2O4 thin films are n-type semiconductor, and LaFeO3 thin films are p-type semiconductor. (3) ZnFe2O4 thin films had sensitivity to acetone, and LaFeO3 thin films had better sensitivity to low-concentration acetone. (4) Doping is an effective way to improve the sensitivity to acetone of LaFeO3 thin films, to decrease the sensitive temperature range.更多还原