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Terahertz ferroelectric soft mode in weakly doped SrTiO.sub.3./sub.: M thin films (M=Mn, Ni, Fe, Co)
- 1.0585184 - FZÚ 2025 RIV NL eng J - Journal Article
Zhukova, E.S. - Nekrasov, B.M. - Tyunina, Marina - Vetokhina, Volha - Kocourek, Tomáš - de Prado, Esther - Stolyarov, V.S. - Frolov, A.S. - Melentev, A.V. - Savinov, Maxim - Bush, A.A. - Kozlov, V.I. - Talanov, M. - Gorshunov, B.P.
Terahertz ferroelectric soft mode in weakly doped SrTiO3: M thin films (M=Mn, Ni, Fe, Co).
Journal of Alloys and Compounds. Roč. 976, Mar (2024), č. článku 173255. ISSN 0925-8388. E-ISSN 1873-4669
R&D Projects: GA ČR(CZ) GA22-10832S; GA MŠMT(CZ) EF16_019/0000760
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760; AV ČR(CZ) StrategieAV21/26
Program: StrategieAV
Institutional support: RVO:68378271
Keywords : Strontium titanate * thin films * soft mode * terahertz spectroscopy
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 6.2, year: 2022
Study of terahertz soft-mode in SrTiO3:M thin (150nm) films doped (2 at%) with transition metals M=Mn, Fe, Ni, Co is performed at freq. 7–1000 cm-1 and temper. 5–300 K. The soft mode dielectric strength and frequency follow the Barrett-like temperature behaviours with unusually high quantum temperatures and large in agnitude negative Curie temperatures, indicating strong destabilization of the ferroelectric state due to a combined effect of quantum fluctuations, dead layers at the boundaries of crystallites, misfit strains within crystallites and disorder induced by doping. Dopant-dependent variation in the asymmetry of the Fano resonance describing coupling of the TO2 phonon and continuum states of polarization fluctuations is observed suggesting presence of polar nanoregions in the films. Correlation between asymmetry parameter and Barrett quantum temperature is observed that highlights the complex character of the local structure-dielectric properties relationships in the films.
Permanent Link: https://hdl.handle.net/11104/0352931
Number of the records: 1