Iron bulk self-diffusion coefficients were measured in Fe2O3 single crystals using original methodology based on the utilization of 57Fe stable isotope as Fe tracer and depth profiling by secondary ion-mass spectrometry. The Fe self-diffusion coefficients were measured along and perpendicular to the c-axis, between 900 and 1100C, in an O atmosphere. Along the c-axis, the coefficients could be described by:

D (cm2/s) = 5.2 x 106 exp[-510(kJ/mol)/RT]

and were close to reliable published data, obtained by means of radioactive techniques. Perpendicular to the c-axis:

D (cm2/s) = 8.3 x 101 exp[-430(kJ/mol)/RT]

and the coefficients were smaller those along the c-axis.

Measurement of Iron Self-Diffusion in Hematite Single Crystals by Secondary Ion-Mass Spectrometry and Comparison with Cation Self-Diffusion in Corundum-Structure Oxides. A.C.S.Sabioni, A.M.Huntz, A.M.J.M.Daniel, W.A.A.Macedo: Philosophical Magazine, 2005, 85[31], 3643-58