In situ investigation of initial stage growth of anodic ZrO_2 nanotubes by spectroscopic ellipsometry

摘要

The highly sensitive spectroscopic ellipsometry (SE) was first employed to in situ monitor the growth of anodic ZrO_2 nanotubes in F?-containing inorganic electrolytewithin the first 80 s anodization. The evolution of the characteristic parameters of anodic ZrO_2 film upon anodization was obtained by deconvoluting the ellipsometric spectra with appropriate models. Four successive phases, namely, formation of compact barrier layer, formation of pores, pore evolution to nanotubes and the nanotube steady-growth, were clearly distinguished during the initial stage of anodization; even the third phase was indiscernible from the i–t curve and likely to be ignored. The growth dynamics of the anodic ZrO_2 film was mainly dependent on that of the porous layer, obeying the linear growth kinetics with a rate of 25.6 nm/s.