The evolution of the electric properties of Nb₂O₅, Ta₂O₅ and WO3 films, at different formation potentials (Ef), in 0.1M HClO4 and 0.1M KOH, were followed with electrochemical impedance spectroscopy (EIS). During the potentiostatic growth, the EIS spectra were acquired every hour, maintaining the potentiostatic pulse during 20h. Nb₂O₅ , Ta₂O₅...
La caracterización de la morfología superficial realizada por microscopia electrónica de barrido (SEM) muestra que estas películas tienen un carácter homogéneo. Sin embargo, el estudio de reactividad superficial mediante espectroscopia fotoelectroquímica de barrido (SPECM), en 0.1M K3[(Fe(CN)6], reveló que éstas son heterogéneas y además, protectoras. La caracterización química superficial por...
In this work, the influence of the predominant iron-sulfate species, on the kinetics of the Fe(lll)/Fe(ll)/H2S0,JH20 redox system, is shown. This was accomplished by: (a) construction of predominance zone, molar fraction and Pourbaix type diagrams, using the generalized species and generalized equilibrium concepts. (b) the experimental determination of the following...