Podrobnosti záznamu

Název
    Antiferrodistortive phase transition in EuTiO3
Autor
    Belik, A.
    Drahokoupil, Jan
    Dušek, Michal
    Fuith, A.
    Goian, Veronica
    Kachlik, M.
    Kamba, Stanislav
    Laufek, František
    Maca, K.
    Pacherová, Oliva
    Palatinus, Lukáš
    Rohlíček, Jan
    Sagarna, L.
    Savinov, Maxim
    Schranz, W.
    Shkabko, A.
    Weidenkaff, A.
Jazyk
    anglicky
Typ dokumentu
    článek v periodiku
Zdrojový dokument - seriál
    Physical Review B
Svazek/č.
    Roč. 86, č. 5
Strany
    9
Rok
    2012
Výraz tezauru
    antiferrodistortive structure, phase transition, X-ray diffraction, infrared reflectivity, EuTiO3
Klíčové slovo
    Antiferrodistortive
    EuTiO3
    Phase
    Transition
Abstrakt (anglicky)
   X-ray diffraction, dynamical mechanical analysis, and infrared reflectivity studies revealed an antiferrodistortive phase transition in EuTiO3 ceramics. Near 300 K, the perovskite structure changes from cubic Pm 3m to tetragonal I4/mcm. Some ceramics as well as single crystals of EuTiO3 show different infrared reflectivity spectra bringing evidence of a different crystal structure. In such samples, electron diffraction revealed an incommensurate tetragonal structure with modulation wave vector q~ 0.38aa*. Extra phonons in samples with modulated structure are activated in the IR spectra due to folding of the Brillouin zone. We propose that defects such as Eu3+ and oxygen vacancies strongly influence the temperature of the phase transition to antiferrodistortive phase as well as the tendency to incommensurate modulation in EuTiO3.
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (RIV)
Zdrojový formát
    R
Datum importu
    15. 10. 2014