Oxygen adatoms at SrTiO3(001): A density-functional theory study

Abstract

We present a density-functional theory study addressing the energetics and electronic structure properties of isolated oxygen adatoms at the SrTiO3(001) surface. Together with a surface lattice oxygen atom, the adsorbate is found to form a peroxide-type molecular species. This gives rise to a non-trivial topology of the potential energy surface for lateral adatom motion, with the most stable adsorption site not corresponding to the one expected from a continuation of the perovskite lattice. With computed modest diffusion barriers below 1 eV, it is rather the overall too weak binding at both regular SrTiO3(001) terminations that could be a critical factor for oxide film growth applications.

Water adsorption and dissociation onSrTiO3(001)revisited: A density functional theory study

“…Another important observation is that the O atom of the protruding hydroxyl group that has formed as a result of the water dissociation process sits in both terminations at the site it would also take in a continuation of the perovskite lattice structure. This is distinctly different to adsorbed O atoms, which we previously found to adsorb in non-perovskite sites 30 . This difference as well as the low mobility of paired hydroxyl groups could be important ingredients towards an atomic-scale understanding of the experimental reports that hydrogen and water increase the growth rate of SrTiO 3 .…”

First-principles investigations of electronic and magnetic properties of SrTiO3(001) surfaces with adsorbed ethanol and acetone molecules

“…These are therefore repelled from the ions underneath in the SrO layer, which are the negatively (positively) charged O (Sr) ions. For the change in the next interlayer spacing d 23 one can see as well from Table I that its values for non-NN of the defect are close to that of the perfect surface, whereas the d 23 increase becomes smaller for NN of the defects.…”

“…[15][16][17][18] Recently theoretical investigations have been published using other molecules such as methanol molecules (CH 3 OH), 19 acetaldehyde (CH 3 CHO), 20 CO, 21 NO, 22 and oxygen adatoms. 23 Like other substrates, STO is usually ultrasonically and chemically cleaned in pure water, acetone, ethanol, or KOH solution in order to remove any trace of impurities which might contaminate the sample during the experiment. Khalid et al 24 recently studied the effect of surface cleaning on the magnetic properties of MgO, MgAl 2 O 4 , SrTiO 3 , LaAlO 3 , and ZnO substrates.…”

First-Principles Modeling of Oxygen Interaction with SrTiO3(001) Surface: Comparative Density-Functional LCAO and Plane-Wave Study

“…On the SrO-terminated substrates, the oxygen adatom is bound more strongly than on TiO 2 -terminated one. Our calculations show that the O ads atoms tend to form the molecular peroxide ions with surface oxygens which is consistent with a recent VASP study [17]. In contrast, on a clean defect-free SrTiO 3 (001) substrate, molecular adsorption is very weak.…”