Broadband dielectric spectroscopy of La.sub.0.65./sub.Sr.sub.0.35./sub.MnO.sub.3./sub.@TiO.sub.2./sub. core–shell nanocomposites

0532986 - FZÚ 2021 RIV GB eng J - Journal Article
Nuzhnyy, Dmitry - Petzelt, Jan - Bovtun, Viktor - Savinov, Maxim - Bednyakov, Petr - Kempa, Martin - Kaman, Ondřej - Levinský, Petr - Hejtmánek, Jiří - Jirák, Zdeněk
Broadband dielectric spectroscopy of La_0.65Sr_0.35MnO₃@TiO₂ core–shell nanocomposites.
Journal of Physics-Condensed Matter. Roč. 32, č. 41 (2020), s. 1-12, č. článku 415701. ISSN 0953-8984. E-ISSN 1361-648X
R&D Projects: GA MŠMT(CZ) EF16_019/0000760; GA ČR GA18-09265S
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271
Keywords : core–shell composite * dielectric spectroscopy * infrared and THz spectroscopy * effective medium approximation * TiO₂
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 2.333, year: 2020
Method of publishing: Limited access
https://doi.org/10.1088/1361-648X/ab997b

Core–shell composites of ferromagnetic conducting nanoparticles La0.65Sr0.35MnO3@TiO2 (LSMO) embedded in an insulating matrix of TiO2 (LSMO@TiO2) have been processed, structurally and magnetically characterized, and their DC magnetoresistivity and complex dielectric response measured and fitted from Hz up to the infrared (IR) range. XRD indicates that the TiO2 shells are amorphous. Modelling of the IR spectra using standard models based on the effective medium approximation has it confirmed and has characterized the effective phonon modes of the LSMO nanoceramics and LSMO@ TiO2 composite. Modelling of the lower-frequency spectra has shown that TiO2 shell thicknesses are rather non-uniform down to thin nm values, which leads to giant low-frequency permittivity values and non-negligible free-carrier tunnelling among the LSMO cores.

Permanent Link: http://hdl.handle.net/11104/0311489