The growth and properties of thin oxide layers on tantalum electrodes

Formation and electric property measurement of nanosized patterns of tantalum oxide by current sensing atomic force microscope

“…This value is in good agreement with previously reported values ͑ϳ2-3 nm͒. [41][42][43] CSAFM measurements were carried out using a PicoSPM microscope ͑Molecular Imaging͒ and a PicoScan controller ͑Molecular Imaging͒. Pattern formation was achieved by applying bias between the Pt coated conductive Pt/Si 3 N 4 tip ͑MikroMasch, typical spring constant: 0.12 N/m, parabolic shape with an apex of the radius of curvature: Ͻ35 nm͒ and the Ta substrate at room temperature ͑ϳ23°C͒ and ambient humidity of ϳ38Ϯ2%.…”

Preparation of Tantalum Anodic Oxide Film in Citric Acid Solution - Evidence and Effects of Citrate Anion Incorporation

“…−0.5 V, no evident current was observed in the positive potential region, showing that the tantalum anodic oxide film is an n-type semiconductor. 22) The anodic current peak observed around −0.75 V should be due to the oxidation of hydrogen. Figure 2 shows Cole-Cole plots of the Ta anodic oxide, which was prepared at the preparation potential of 10 V in 0.1 M citric acid aqueous solution, measured −0.85, −0.60, 0.0, and +1.50 V. AC impedance measurements also showed n-type semiconducting property, supporting the result of the cyclic voltammetry.…”

Physicochemical Characterization of Passive Films and Corrosion Layers by Differential Admittance and Photocurrent Spectroscopy

“…On the other hand semiconducting passive films in a large range of thickness (2 ~ 74 whilst at large film thickness the same transition may occur with increasing ac signal frequency. [75][76][77][78] In this frame the theory of amorphous semiconductor Schottky barrier provides a unified approach to the theory of electrical admittance of electrode/electrolyte junction including as limiting case the ideal SC/electrolyte junction on which the traditional M-S approach is based.…”