Low-energy electron microscopy was used to show that changing the temperature of oxygen-deficient rutile-structured crystals caused steps on the (110) surfaces to move. This motion occurred because the concentration of bulk oxygen vacancies changes with temperature, requiring that material be added to or subtracted from the surface. During cooling below a bulk-stoichiometry-dependent temperature, the surface reconstructs into a 1 x 2 structure in the regions surface steps have swept through, showing that the structural and compositional changes needed to form the 1 x 2 phase were facilitated by the surface-to-bulk mass flow.

Role of Bulk Thermal Defects in the Reconstruction Dynamics of the TiO2(110) Surface. McCarty, K.F., Bartelt, N.C.: Physical Review Letters, 2003, 90[4], 046104