Description
Polarons are quasiparticles that form in polarizable materials, via coupling of excesselectrons or holes with lattice vibrations [1]. These quasiparticles have raised large interest in
our scientific community due to their profound impact on structural, electrical and chemical
properties of the hosting materials. Nowadays formation of polarons can be investigated by
several experimental techniques, and described in well developed theoretical frameworks.
This seminar will start with a description of the fundamental aspects of polarons,
highlighting some of the techniques typically adopted in modern studies. The final part will
focus on disclosing the impact of polarons in applications, by discussing their role in surface
reactivity. Specifically, it will be shown how the puzzling adsorption of CO molecules
adsorbed on rutile TiO 2 (110) surface can be solved by considering the complex interactions
with polaronic states in the materials: attractive coupling with polarons on the surface layer in
the proximity of oxygen vacancy defects, and repulsive interaction with polarons in
subsurface layers [2]. Finally, the CO adsorption on the polar KTaO 3 (001) surface will offer
us the possibility to address novel aspects, such as the stabilization of particularly strongly
localized states on defect-free terminations, and their interplay with intrinsic ferroelectric
distortions.
| Period | 20 May 2021 |
|---|---|
| Held at | Charles University Prague, Czech Republic |