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

作者：Alexandrov Vitaly; Piskunov Sergei^*; Zhukovskii Yuri F; Kotomin Eugene A; Maier Joachim

来源：Integrated Ferroelectrics, 2011, 123: 10-17.

DOI：10.1080/10584587.2011.570586

Large scale first-principles calculations based on density functional theory (DFT) employing two different methods (atomic orbitals and plane wave basis sets) were used to study the energetics, geometry, the electronic charge redistribution and migration for adsorbed atomic and molecular oxygen on defect-free SrTiO3(001) surfaces (both SrO- and TiO2-terminated), which serves as a prototype for many ABO(3)-type perovskites. Both methods predict substantial binding energies for atomic O adsorption at the bridge position between the oxygen surface ions and an adjacent metal ion. A strong chemisorption is caused by formation of a surface molecular peroxide ion. In contrast, the neutral molecular adsorption energy is much smaller, similar to 0.25 eV. Dissociative molecular adsorption is energetically unfavorable, even at 0 K. Adsorbed O atoms migrate along the (001) direction with an activation energy of similar to 1 eV which is much larger than that for surface oxygen vacancies (0.14 eV). Therefore, the surface O vacancies control encounter with the adsorbed O atoms and oxygen penetration to the surface which is the limiting step for many applications of ABO(3)-type perovskites, including resistive oxygen sensors, permeation ceramic membranes and fuel cell technology.

• 出版日期2011