Reversible Transition Between Thermodynamically Stable Phases with Low   Density of Oxygen Vacancies on SrTiO$_3$(110) Surface
  The surface reconstruction of SrTiO$_3$(110) is studied with scanning tunneling microscopy and density functional theory (DFT) calculations. The reversible phase transition between (4$\times$1) and (5$\times$1) is controlled by adjusting the surface metal concentration [Sr] or [Ti]. Resolving the atomic structures of the surface, DFT calculations verify that the phase stability changes upon the chemical potential of Sr or Ti. Particularly, the density of oxygen vacancies is low on the thermodynamically stabilized SrTiO$_3$(110) surface. 
Fengmiao Li, Zhiming Wang, Sheng Meng, Yongbao Sun, Jinlong Yang,   Qinlin Guo, and Jiandong Guo
cond-mat.mtrl-sci