Michael Woldemedhin, Dierk Raabe, Hrg. Achim Walter Hassel,
"Anodic oxides on beta type Nb-Ti alloy and their characterization by electrochemical impedance spectroscopy"
, in Physica Status Solidi A: Applications and Materials Science, Vol. 207, Seite(n) 812-816, 2010, ISSN: 1862-6300
Original Titel:
Anodic oxides on beta type Nb-Ti alloy and their characterization by electrochemical impedance spectroscopy
Sprache des Titels:
Englisch
Original Kurzfassung:
Anodic oxides were grown on the surface of an electropolished (Ti-30 at% Nb) beta-titanium (ß-Ti) alloy by cyclic voltammetry. The scan rate was 100 mV s-1 between 0 and 8 V in increments of l V in an acetate buffer of pH 6.0. Electrochemical impedance spectroscopy was carried out right after each anodic oxide growth increment to study the electronic properties of the oxide/electrolyte interface in a wide frequency range from 100 kHz to 10 MHz with an AC perturbation voltage of 10 mV. A film formation factor of 2.4 nm V-1 was found and a relative permittivity number (dielectric constant) of 42.4 was determined for the oxide film formed. Mott-Schottky analysis on a potentiostatically formed 7 nm thick oxide film was performed to assess the semiconducting properties of the mixed anodic oxide grown on the alloy. A flat band potential of -0.47 V (standard hydrogen electrode, SHE) was determined, connected to a donor density of 8.2 × 1017 cm-3. ß-Ti being highly isotropic in terms of mechanical properties should be superior to the stiffer alpha-Ti compound. Its application, however, requires a passivation behaviour comparable or better than alpha-Ti which in fact is found.
Sprache der Kurzfassung:
Englisch
Journal:
Physica Status Solidi A: Applications and Materials Science
Volume:
207
Seitenreferenz:
812-816
Erscheinungsjahr:
2010
ISSN:
1862-6300
Anzahl der Seiten:
5
Notiz zur Publikation:
1)Max-Planck-Institut für Eisenforschung, Max-Planck-Str.1, 40237 Düsseldorf, Germany
2)Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University, Linz, Austria
- 1,2Achim Walter Hassel, 1,2Michael Teka Woldemedhin, 1Dierk Raabe