Gas sensing properties of nanocrystalline La0.75Ba0.25FeO3 thick-film sensors

In the present work, La0.75Ba0.25FeO3 thick films were fabricated by printing the paste (a mixture of La0.75Ba0.25FeO3 powders and binder) on an alumina substrate pre-deposited with Ag electrodes. After the printing process, the thick films were annealed at various temperatures. When the La0.75Ba0.25FeO3 powders were prepared through annealing at 800 °C for 3 h, the optimal final annealing temperature was about 700 °C for the La0.75Ba0.25FeO3 thick film to obtain a large sensing response. The gas sensing properties of La0.75Ba0.25FeO3 thick-film sensors depended on the film thickness. The film with thickness of D = 50 μm exhibited the largest response among the four thick films (D = 30, 50, 70, and 100 μm). La0.75Ba0.25FeO3 thick-film sensors could detect acetone and ethanol with very low concentrations (e.g., 5 ppm).