Ra. Bennett et al., STM and LEED observations of the surface structure of TiO2(110) following crystallographic shear plane formation, PHYS REV B, 59(15), 1999, pp. 10341-10346
Extended vacuum annealing of rutile TiO2(110) produces macroscopic and nano
scopic changes in the surface morphology. These result from the ordering of
oxygen vacancies/Tin+ interstitials in bulk TiO2 into crystallographic she
ar (CS) planes. We have employed low-energy electron diffraction (LEED) and
scanning tunnelling microscopy (STM) to identify the surface termination o
f CS planes produced in the bulk. The directions of the planar defects alon
g the surface indicate the {132} series of shear planes dominate the STM im
ages, which is also supported by the LEED results. The spacing between plan
es gradually varies across the surface suggesting that a series of Magneli
phases are formed. LEED patterns confirm the coexistence of both relatively
large areas of a single phase and a continuum of separations between plane
s. Formation of CS planes also leads to extensive facetting of the crystal,
which is visible to the naked eye as a rippled surface finish. Some Ca seg
regation is observed during CS plane formation; however, when removed the C
S planes remain, indicating they are not significantly stabilized by the Ca
. [S0163-1829(99)02215-8].