APPLYING POLARIZED ELECTROCHEMICAL VAPOR-DEPOSITION (PEVD) FOR AUXILIARY PHASE DEPOSITION AT WORKING ELECTRODES OF GASEOUS OXIDE SENSORS

Solid-state electrolyte potentiometric sensors with auxiliary phases a re promising for the detection of gaseous oxides. In order to establis h a gas electrode reaction model involving auxiliary phases, the basic sensing processes for this kind of sensor are discussed within the fr amework of Wagner's theory. According to the model, six general criter ia, related to the geometric aspects of the auxiliary phases at sensor working electrodes, are proposed for improving the sensing performanc e. Based on this understanding, it appears that a new thin film deposi tion technique, Polarized Electrochemical Vapor Deposition (PEVD), is the most suitable to apply auxiliary phases. (C) 1997 Elsevier Science S.A.