Cr GRAIN BOUNDARY DIFFUSION IN Cr2O3

Abstract

Cr grain boundary diffusion has been measured in dense polycrystals of Cr2O3 using 54Cr as a stable tracer and depth profiling by SIMS. At 1200 and 1300°C, in an oxygen pressure of 5.10-5 atm, (5 Pa), it was found 1.03.10-15 and 4.72.10-14 cm2.s-1 respectively for the grain boundary diffusion, considering the width of the grain boundary equal to 1 nm and using lattice diffusion values obtained on single crystals (1.0.10-18 cm2.s-1 at 1200°C and 4.8.10-18 cm2.s-1 at 1300°C). These values are smaller than those previously published in the same range of temperatures and oxygen pressure.