Influence of gas adsorption and diffusion on the capacitance and resistance response in SnO2 thick-films

M. A. PONCE, J.E. RODRÍGUEZ PÁEZ, J. FRUTOS, M. S. CASTRO

Toledo, España

Congreso; Electroceramics X; 2006

  Abstract            Tin oxide powders obtained through the Pechini´s method were deposited onto insulating alumina substrates with Au electrodes.  Impedance studies on SnO2 thick films in an air atmosphere were carried out. Capacitance and resistance analyses show the impedance dependence with potential barrier height and donor concentration. Schottky-type potential barriers at grain boundaries were assumed to analyze the sample conductance. Possible mechanisms responsible for the experimental responses were proposed.  The influence of temperature on the oxygen diffusion into the grains annihilating oxygen vacancies was detected. In particular, we found the transition from separated to overlapped potential barriers.