Abstract:Bi_3.15Nd_0.85Ti₃O₁₂ (BNdT) films were deposited on Pt/Ti/SiO₂/Si(100) substrates by a metal organic decomposition (MOD) method, and annealed by a rapid thermal annealing process in oxygen atmosphere and in air, respectively. The crystalline structures and morphologies of BNdT films were characterized by X-ray diffraction and field-emission scanning electron microscopy, and the gas sensing properties were measured by monitoring its resistance at different gas concentrations. The results indicate that the BNdT films annealed in air are of porous microstructure and rough surface, and the annealing atmosphere has great influence on gas sensing properties. At an operating temperature of 100 °C, the BNdT films annealed in air are of high response value to 1×10^-6 gaseous ethanol, and the detecting limit is as low as 0.1×10^-6. The corresponding response and recovery time is about 10 and 6 s, respectively. The results can offer useful guidelines for fabricating high performance ethanol sensors.

Key words: BNdT film; ethanol sensing properties; metal organic decomposition; annealing atmosphere; low operating temperature