Title:	Small-Polaron Hopping and Low-Temperature (45–225 K) Photo-Induced Transient Absorption in Magnesium-Doped Lithium Niobate
Authors:	Messerschmidt, Simon Krampf, Andreas Vittadello, Laura Imlau, Mirco Nörenberg, Tobias Eng, Lukas M. Emin, David
ORCID of the author:	https://orcid.org/0000-0001-6193-7487 https://orcid.org/0000-0001-8023-0946 https://orcid.org/0000-0002-2484-4158 https://orcid.org/0000-0001-5790-9379 https://orcid.org/0000-0002-5343-5636
Abstract:	A strongly temperature-dependent photo-induced transient absorption is measured in 6.5 mol% magnesium-doped lithium niobate at temperatures ranging from 45 K to 225 K. This phenomenon is interpreted as resulting from the generation and subsequent recombination of oppositely charged small polarons. Initial two-photon absorptions generate separated oppositely charged small polarons. The existence of these small polarons is monitored by the presence of their characteristic absorption. The strongly temperature-dependent decay of this absorption occurs as series of thermally assisted hops of small polarons that facilitate their merger and ultimate recombination. Our measurements span the high-temperature regime, where small-polaron jump rates are Arrhenius and strongly dependent on temperature, and the intermediate-temperature regime, where small-polaron jump rates are non-Arrhenius and weakly dependent on temperature. Distinctively, this model provides a good representation of our data with reasonable values of its two parameters: Arrhenius small-polaron hopping’s activation energy and the material’s characteristic phonon frequency.
Citations:	Messerschmidt, S.; Krampf, A.; Vittadello, L.; Imlau, M.; Nörenberg, T.; Eng, L.M.; Emin, D.: Small-Polaron Hopping and Low-Temperature (45–225 K) Photo-Induced Transient Absorption in Magnesium-Doped Lithium Niobate. Crystals 2020, 10, 809.
URL:	https://osnadocs.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-202105184716
Subject Keywords:	lithium niobate; small polaron hopping; transient absorption
Issue Date:	14-Sep-2020
License name:	Attribution 4.0 International
License url:	http://creativecommons.org/licenses/by/4.0/
Type of publication:	Einzelbeitrag in einer wissenschaftlichen Zeitschrift [article]
Appears in Collections:	FB06 - Hochschulschriften Open-Access-Publikationsfonds

This item is licensed under a Creative Commons License