Small Polaron Formation on the Nb-doped SrTiO<sub>3</sub>(001) Surface
- Author(s)
- Florian Ellinger, Muhammad Shafiq, Iftikhar Ahmad, Michele Reticcioli, Cesare Franchini
- Abstract
The cubic perovsike strontium titanate SrTiO$_3$ (STO) is one of the most studied, polarizable transition metal oxides. When excess charge is introduced to this material, e.g., through doping or atomic defects, STO tends to host polarons: Quasi-particles formed by excess charge carriers coupling with the crystal phonon field. Their presence alters the materials properties, and is a key for many applications. Considering that polarons form preferentially on or near surfaces, we study small polaron formation at the TiO$_2$ termination of the STO(001) surface via density functional theory calculations. We model several supercell slabs of Nb-doped and undoped STO(001) surfaces with increasing size, also considering the recently observed as-cleaved TiO$_2$ terminated surface hosting Sr-adatoms. Our findings suggest that small polarons become less stable at low concentrations of Nb-doping, in analogy with polarons localized in the bulk. Further, we inspect the stability of different polaron configurations with respect to Nb- and Sr-impurities, and discuss their spectroscopic properties.
- Organisation(s)
- Computational Materials Physics
- External organisation(s)
- University of Bologna, Abbottabad University of Science and Technology, University of Malakand (UOM)
- Journal
- Physical Review Materials
- Volume
- 7
- No. of pages
- 9
- ISSN
- 2475-9953
- DOI
- https://doi.org/10.48550/arXiv.2208.10624
- Publication date
- 06-2023
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103015 Condensed matter
- Keywords
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/d3ffe06a-bd18-46ca-a9a6-60bc633b552a