EFFECT OF UV-RADIATION ON THE GROWTH AND BREAKDOWN VOLTAGE OF ANODIC OXIDE-FILMS ON NIOBIUM

Formation rates of anodic Nb2O5 films grown under galvanostatic condit ions decrease in the presence of UV radiation, unlike those grown in t he absence of UV radiation. This may be due to the development of a po sitive space charge near the solution/oxide interface which is respons ible for an increase in electronic current in the film during its form ation. Value of breakdown voltage also increases in the presence of UV radiations. The effect of current density and resistivity of the solu tion upon the breakdown voltage, both in the presence and absence of U V radiation, is discussed in terms of Ikonopisov theory of breakdown v oltage.