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  • 1
    Electronic Resource
    Electronic Resource
    Effect of short-circuiting on the oxidation kinetics of copper and its doped varieties in the temperature range of 523–1073 K (1996)
    Springer
    Oxidation of metals 46 (1996), S. 73-107 
    Details
    ISSN: 1573-4889
    Keywords: oxidation ; copper ; Li-doped copper ; Cr-doped copper ; short-circuiting ; Mott's parabola ; Wagner's parabola
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The influence of shorting circuitry attachment between metal-oxide and oxideoxygen interfaces on the oxidation kinetics of copper, lithium-doped copper (Li: 400 ppm), and chromium-doped copper (Cr: 12 ppm) have been studied in dry air $$(P_{O_2 } = 21.27kPa)$$ in the temperature range of 523–1073 K. Oxide film or scale growth under short-circuiting as well as under normal oxidation conditions conforms to the parabolic rate law. The oxidation kinetics under short-circuiting resulted in decreased rates for Cu and Li-doped Cu up to a temperature of 773 K, while Cr-doped Cu exhibited an enhancement in rate compared to its normal oxidation in the same temperature range. However, above 873 K, all three systems under shorting circuitry attachment exhibited enhanced rates compared to their normal oxidation rates in conformity to the existing theoretical model. Use of additional resistances in series in the outer short-circuit Pt path have clearly established that below 773 K Mott's fieldinduced migration plays the most important role, while at elevated temperatures Wagner's electrochemical potential-gradient factor acts as the main driving force in the scale-growth process. The results have been interpreted on the basis of average defect concentration, the electrochemical potential gradient, electrical field gradient, and transport coefficient in the Cu2O layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01046885
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  • 2
    Electronic Resource
    Electronic Resource
    A critical appraisal of the logarithmic rate law in thin-film formation during oxidation of copper and its alloys (1981)
    Springer
    Oxidation of metals 15 (1981), S. 9-20 
    Details
    ISSN: 1573-4889
    Keywords: oxidation ; logarithmic law ; copper ; copper alloys ; activation energy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Investigations have been carried out on the kinetics of thin film formation of copper and its alloys in the temperature range of 75–100°C. The experimental results have been found to follow the logarithmic rate law except for the copper-chromium system at 100°C. The kinetic data have been analyzed in light of William and Hayfield's theory, and the various parameters of the logarithmic rate equation match very well to those calculated by others. The estimated activation energy value did not show significant variation. The major contribution to the rate of film growth has been ascribed to the available number of Fermi electrons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00603754
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Oxidation behavior of copper at high temperatures under two different modes of direct-current applications (1995)
    Springer
    Oxidation of metals 43 (1995), S. 185-215 
    Details
    ISSN: 1573-4889
    Keywords: copper ; oxidation ; direct current ; uninterrupted mode ; interrupted mode
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Oxidation kinetics of copper in the temperature range of 973–1173 K atP O 2=21.27 kPa exhibit enhancement and deceleration in the rates with changing polarity compared to normal oxidation under interrupted mode of directcurrent application. These conditions are achieved by connecting the oxidizing copper covered with an initially formed thin oxide film to the positive and negative terminal of a dc source, respectively. However, the influence of direction of the current is found to be opposite under uninterrupted mode of impressed current flow in the same temperature range. The effect of short-circuiting the metal to the outer oxide/air interface on the reaction kinetics is also reported. The rate of oxide-scale growth under normal condition, and two different modes of current applications as well as with shorting circuitry attachment conform to the parabolic growth law. The results pertaining to the two different modes of impressed current have been discussed considering both the phenomena of electrolysis of the oxide electrolyte and the polarization at the two phase boundaries. The enhancement and the reduction in rates under uninterrupted impressed current conditions are explained on the basis of increased and decreased average defect concentrations, respectively, within the oxide layer. The acceleration and deceleration in the rates under interrupted mode of current flow have been explained in the light of sustenance of a steeper and flatter electrochemical-potential gradient of defects, respectively, across the growing-oxide layer. The possible different responses of the metal/oxide and oxide/air interfaces to the impressed current brought into play by two different modes of current application, have enabled to display a better insight on the mechanistic aspects of scale growth under the influence of an externally applied current.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01047027
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  • 4
    Electronic Resource
    Electronic Resource
    Pressure dependencies of copper oxidation for low- and high-temperature parabolic laws (1991)
    Springer
    Oxidation of metals 35 (1991), S. 1-18 
    Details
    ISSN: 1573-4889
    Keywords: copper ; oxidation ; parabolic laws ; pressure dependence ; defects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Studies of the oxidation kinetics of copper have been conducted in the thin-film range at temperatures of 383–398 K and in the oxygen pressure range of 0.278–21.27 kPa; whereas in the thick-film regime at 1123 K, studies have been conducted in the oxygen pressure range of 2.53–21.27 kPa. Furthermore, the effect of continuously impressed direct current with oxygen pressure variation in Wagner's parabolic range has been studied also in order to have a better understanding of the effective charge on the migrating species. In the low-temperature range, the rate constant, kP ∝ $$P_{O_2 }^{1/4} $$ , suggesting that the migration of neutral vacancies in the growing film predominates. At high temperature, 1123 K, in the Wagnerian regime, the observed approximate pressure dependencies of the parabolic rate constants are the following: $$\begin{gathered} {\text{k}}_{\text{p}} (normal oxidation) \propto \sim {\text{P}}_{{\text{O}}_{\text{2}} }^{{\text{1/7}}} \hfill \\ {\text{k}}_{\text{p}} (sample cathodic) \propto \sim {\text{P}}_{{\text{O}}_{\text{2}} }^{{\text{1/5}}} \hfill \\ \end{gathered} $$ and $${\text{k}}_{\text{p}} (sample anodic) \propto \sim {\text{P}}_{{\text{O}}_{\text{2}} }^{{\text{1/10}}} $$ .
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00666497
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    Paper (German National Licenses)
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