Chemical diffusion measurements in single crystalline cuprous oxide

Using electrical conductivity measurements in the temperature range 650–1100°C and for oxygen pressure greater than 10^?6atm., the variation of the chemical diffusion coefficient in cuprous oxide with temperature has been determined as:

$\text{D}\text{?}\text{= 1.2 10}{}^{\mathrm{?3}}\text{exp}\text{(}\text{? 7800}\text{RT}\text{)}\text{cm}{}^2\text{sec}{}^{\mathrm{?1}}$

.Taking into account the nature of the prevailing defects in cuprous oxide one can show that $\text{D}\text{?}\text{?D}{}_{\mathrm{<mtext>Cu</mtext>}}\text{V}{}^{\mathrm{x}}{}_{\mathrm{<mtext>Cu</mtext>}}\text{]}$. This relation permits the results to be compared with those determined by tracer diffusivities. Using a value for the enthalpy of formation of non ionized copper vacancies in the range 12–16 kcal mol^?1, the results are shown to be in agreement with the value of the activation enthalpy for self-diffusion of copper of 24 kcal mol^?.