Structure determination of the two-domain (1 x 4) anatase TiO2(001) surface

The reconstructed anatase TiO2(001) surface has been investigated by low-en ergy electron diffraction (LEED), x-ray photoelectron spectroscopy (XPS), a nd angle-resolved mass spectroscopy of recoiled ions (AR-MSRI). Prior inves tigations have observed or considered only a (1 x 1) unreconstructed termin ation for this surface with no detailed structural analysis. Our LEED resul ts indicate a previously unobserved two-domain (1 x 4) reconstruction after sputtering and annealing the (I x 1) surface. The XPS data for this recons truction indicate the presence of only Ti4+. Simulations of the AR-MSRI exp erimental data indicate a best fit for a microfaceted surface, revealing bo th. (103) and ((1) over bar 03) surface planes.