Structure of the Reduced TiO2(110) Surface Determined by Scanning Tunneling Microscopy

Science  30 Nov 1990:
Vol. 250, Issue 4985, pp. 1239-1241
DOI: 10.1126/science.250.4985.1239


The scanning tunneling microscope has been used to image a reduced TiO2(110) surface in ultrahigh vacuum. Structural units with periodicities rangng from 21 to 3.4 angstroms have been clearly imaged, demonstrating that atomic resolution imaging of an ionic, wide band gap (3.2 electron volts) semiconductor is possible. The observed surface structures can be explained by a model involving ordered arrangements of two-dimensional defects known as crystallographic shear planes and indicate that the topography of nonstoichiometric oxide surfaces can be complex.