Studies On Iron Compound Oxides For Acetone Gas Sensor Materials

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.