The Rosenburg method was used to determine the physicochemical properties of the oxide at 900 to 1000C, under O pressures ranging from 0.005 to 0.1atm. The defect concentration was proportional to the fourth root of the O partial pressure, while the defect diffusion coefficient was essentially independent of the ambient O pressure. This was explained by assuming that it reflected a predominance of neutral Cu vacancies. The formation enthalpy of neutral Cu vacancies was observed to be about 60kJ/mol, while the formation entropy was about -11J/molK. The migration enthalpies and entropies, as calculated from the temperature dependence of defect diffusion, were about 54kJ/mol and 5.8J/molK, respectively. Combining the enthalpies of formation and migration of vacancies yielded an enthalpy for Cu self-diffusion of about 115kJ/mol.

Determination of Thermodynamics and Kinetics of Point Defects in Cu2O using the Rosenburg Method. R.Haugsrud, T.Norby: Journal of the Electrochemical Society, 1999, 146[3], 999-1004