Structure Determination of the Two-Domain (1×4) AnataseTiO2(001)Surface

The reconstructed anatase ${\mathrm{TiO}}_2\left(001\right)$ surface has been investigated by low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy (XPS), and angle-resolved mass spectroscopy of recoiled ions (AR-MSRI). Prior investigations have observed or considered only a $(1\times 1)$ unreconstructed termination for this surface with no detailed structural analysis. Our LEED results indicate a previously unobserved two-domain $(1\times 4)$ reconstruction after sputtering and annealing the $(1\times 1)$ surface. The XPS data for this reconstruction indicate the presence of only ${\mathrm{Ti}}^{4+}$. Simulations of the AR-MSRI experimental data indicate a best fit for a microfaceted surface, revealing both (103) and $\left(\overline{1}03\right)$ surface planes.