Polar phonon mixing in magnetoelectric EuTiO3.
Result description
Infrared reflectivity spectra of antiferromagnetic incipient ferroelectric EuTiO3 were investigated up to 600 K. Analysis of phonon plasma frequencies showed that the lowest-energy TO1 phonon correspond predominantly to the Slater mode describing vibration of Ti cations against the oxygen octahedra. TO2 phonon expresses vibrations of Eu cation against the TiO6 octahedra and the highest frequency phonon represents O-octahedra bending. Incipient ferroelectric behavior of the permittivity is caused by pronounced softening of the TO1 phonon, which is coupled to the TO2 mode. Although the Eu cations are not involved in the TO1 mode, the spin ordering of the 4f electrons at Eu cations has influence on the frequency of TO1 mode due to its coupling with TO2 mode as the consequence of superexchange interaction. This is probably responsible for 7% change of the permittivity induced by magnetic field in antiferromagnetic phase, as rep. by Katsufuji and Takagi (Phys. Rev. B 64, 054415 (2001)).
Keywords
The result's identifiers
Result code in IS VaVaI
Result on the web
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DOI - Digital Object Identifier
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Alternative languages
Result language
angličtina
Original language name
Polar phonon mixing in magnetoelectric EuTiO3.
Original language description
Infrared reflectivity spectra of antiferromagnetic incipient ferroelectric EuTiO3 were investigated up to 600 K. Analysis of phonon plasma frequencies showed that the lowest-energy TO1 phonon correspond predominantly to the Slater mode describing vibration of Ti cations against the oxygen octahedra. TO2 phonon expresses vibrations of Eu cation against the TiO6 octahedra and the highest frequency phonon represents O-octahedra bending. Incipient ferroelectric behavior of the permittivity is caused by pronounced softening of the TO1 phonon, which is coupled to the TO2 mode. Although the Eu cations are not involved in the TO1 mode, the spin ordering of the 4f electrons at Eu cations has influence on the frequency of TO1 mode due to its coupling with TO2 mode as the consequence of superexchange interaction. This is probably responsible for 7% change of the permittivity induced by magnetic field in antiferromagnetic phase, as rep. by Katsufuji and Takagi (Phys. Rev. B 64, 054415 (2001)).
Czech name
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Czech description
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Classification
Type
Jx - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
BM - Solid-state physics and magnetism
OECD FORD branch
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Result continuities
Project
Continuities
Z - Vyzkumny zamer (s odkazem do CEZ)
Others
Publication year
2009
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
European Physical Journal B
ISSN
1434-6028
e-ISSN
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Volume of the periodical
71
Issue of the periodical within the volume
3
Country of publishing house
DE - GERMANY
Number of pages
5
Pages from-to
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UT code for WoS article
000271029200021
EID of the result in the Scopus database
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Result type
Jx - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP
BM - Solid-state physics and magnetism
Year of implementation
2009