Croatica Chemica Acta, Vol. 83 No. 2, 2010.
Original scientific paper
Photoelectrochemical Study of Anodically Formed Oxide Films on Niobium Surfaces
Irena Mickova
; Faculty of Technology and Metallurgy, Ss. Cyril and Methodius University in Skopje, Ruger Boskovic 16, 1000 Skopje, Republic of Macedonia
Abstract
The semi-conducting properties of electrochemically formed oxide films onto Nb surface in 1 M
H2SO4 have been studied by photo-electrochemical measurements. By cyclic voltammetry the I vs. E profile of active/passive transition of Nb electrode has been recorded in the potential region from –0.5 to
8 V (SCE). The photocurrent maximums, band gap energies and flat potentials of anodic oxide films formed by stepwise rising of anodic voltage from 10 to 100 V on Nb electrode have been determined. Using Raman spectroscopy the development of crystalline structure in the films with different resultant
thickness has been analysed. The semi-conducting properties of niobium oxides with development of
crystalline structure have been discussed in term of breakdown processes in the films. The thresholds of
transition from amorphous to crystalline form of anodic oxide films depending of applied voltages and
time of polarization have been determined.
Keywords
Nb anodic films; photocurrent spectra; Raman spectroscopy
Hrčak ID:
56010
URI
Publication date:
15.7.2010.
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