The (1 x 2) reconstruction of the α-Fe2O3 (¯10•2) surface was reconsidered in order to answer questions of compositional and in-depth extension of the reconstructed layers. Low-energy electron diffraction and Auger electron spectroscopy were used to study modifications of the surface structure and composition as a function of various in situ treatments. The extension in depth of the (1 x 2) reconstruction increased with ultra-high vacuum annealing temperature (from 400 to 1000C, pO2 = 10−10mbar). Extending over several repeat units of the (¯10•2) stacking sequence, the reconstructed layer reached about 30Å after 900C annealing. A model of an ordered oxygen deficient layer was proposed in which one half of the octahedral iron sites was replaced by ordered tetrahedral ones.

The (1 x 2) Reconstruction of the α-Fe2O3 ¯10•2 Surface. M.Gautier-Soyer, M.Pollak, M.Henriot, M.J.Guittet: Surface Science, 1996, 352-354, 112-6