A System for the Determination of Oxidation—Reduction Kinetics in Nonstoichiometric Metal Oxides

  • I. Bransky
  • N. M. Tallan


The chemical diffusion coefficient can be determined from measurements of the kinetics of oxidation or reduction of a nonstoichiometric metal oxide. To accomplish this thermogravimetrically when the homogeneity range of the oxide is small, all disturbing influences and sources of noise, such as gas-flow irregularities and temperature gradient variations, must be minimized. A system is described which delivers high gas flows at constant pressure and flow rate to the furnace and switches rapidly from one oxygen partial pressure to another with minimum disturbance to the Cahn RG Electrobalance® used. The importance of linear gas velocity and furnace geometry when using CO — CO2 mixtures is discussed and a satisfactory gas preheater is described. An example of the application of the apparatus to the reduction of MnO1+X in steps of Δx ≈ 0.2% is presented.


Oxygen Partial Pressure Chemical Diffusion Reduction Kinetic Chemical Diffusion Coefficient Metal Vacancy 
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Copyright information

© Plenum Press, New York 1971

Authors and Affiliations

  • I. Bransky
    • 1
  • N. M. Tallan
    • 2
  1. 1.Ohio State University Research FoundationUSA
  2. 2.Aerospace Research LaboratoriesWright-Patterson Air Force BaseDaytonUSA

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