Small-polaron conductivity in perovskite ferroelectric BaTiO.sub.3./sub. films

0566635 - FZÚ 2023 RIV US eng J - Journal Article
Tyunina, Marina - Savinov, Maxim - Dejneka, Alexandr
Small-polaron conductivity in perovskite ferroelectric BaTiO₃ films.
Applied Physics Letters. Roč. 121, č. 20 (2022), č. článku 202901. ISSN 0003-6951. E-ISSN 1077-3118
R&D Projects: GA MŠMT(CZ) EF16_019/0000760; GA ČR(CZ) GA22-10832S
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271
Keywords : electron polarons * excitons
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4, year: 2022
Method of publishing: Limited access
https://doi.org/10.1063/5.0129831

Small-polaron hopping conductivity was evidenced and examined in various pulsed-laser-deposited films of ferroelectric BaTiO3 and reference films of SrTiO3. For this, AC conductivity was studied in a broad range of temperatures and frequencies for films sandwiched between the bottom and top electrodes. In the BaTiO3 films, with increasing temperature, a significant increase in activation energy for small-polaron hopping was found and ascribed to strong electron–phonon coupling and complex lattice oscillations therein. Plain relations of the activation energy to microstructure, composition, or phase transitions were lacking, which corroborated the critical role of phonons. Additionally, a phonon-less transport was detected. It was anticipated that owing to strong electron–phonon coupling, rich phonon ensembles, and coexistence of phonon-stimulated and phonon-less processes, the small-polaron conductivity can heavily vary in ferroelectric films that necessitates further studies.
Permanent Link: https://hdl.handle.net/11104/0337954