Elaboration and characterization of doped barium titanate films for gas sensing
Résumé
Barium titanate (BaTiO3) thick films were prepared from commercial powder to develop and optimize the filmelaboration. Then, BaTiO3was doped by strontium and iron to increase the conductivity by a double substitution on siteA and B of the perovskite structure in view to develop semiconductor gas sensors. Film inks were prepared by mixing BTand BSTF powder with an organic vehicle, using a ratio of 50:50; 60:40, respectively and deposited on aluminasubstrates. The BT and BSTF films were sintered at 1100°C for 2h. The structural and physical properties of the filmshave been studied by using X-ray diffraction (XRD) and scanningelectron microscope (SEM). The dielectricmeasurements showed a huge increase in the a.c. conductivity for the BSTF films, by a factor of 10000 at low frequency,when the temperature ranges from 25°C to 500°C.