Počet záznamů: 1  

Terahertz–infrared electrodynamics of overdoped manganites La.sub.1-x./sub.Ca.sub.x./sub.MnO.sub.3./sub

  1. 1.
    0439482 - FZU-D 2015 RIV GB eng J - Článek v odborném periodiku
    Kadyrov, L.S. - Gorshunov, B.P. - Zhukova, E.S. - Torgashev, V. I. - Prokhorov, A. S. - Motovilova, E.A. - Fischgrabe, F. - Moshnyaga, V.T. - Zhang, T. - Kremer, R. K. - Pracht, U. - Zapf, S. - Pokorný, Jan - Untereiner, G. - Kamba, Stanislav - Dressel, M.
    Terahertz–infrared electrodynamics of overdoped manganites La1-xCaxMnO3
    Phase Transitions. Roč. 87, 10-11 (2014), s. 1050-1059. ISSN 0141-1594
    Institucionální podpora: RVO:68378271
    Klíčová slova: manganites * terahertz
    Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
    Impakt faktor: 0.954, rok: 2014

    We have measured low-temperature terahertz and infrared spectra of La1–xCa xMnO3 with x = 0.5; 0.6; 2/3, 0.7; 3/4, 0.85; 0.9; 0.95; 0.98 and x = 1 in the form of ceramics and epitaxial films. In the charge-ordered state for commensurate dopings (x = 2/3 and 3/4), we observed an absorption band at frequencies corresponding to the position of the lowest energy van Hove singularity in the folded Brillouin zone. The band is assigned to the boson peak. We observed qualitatively the same boson peak in Raman spectra of La1/3Ca2/3MnO3 ceramics. In antiferromagnetic phase, for the 0.5 ≤ x < 0.85 range of doping, the conductivity mechanism gradually changes from a hopping-like transport at low temperatures to the Drude behavior at elevated temperatures in the paramagnetic phase. For 0.85 ≤ x < 1 (canted antiferromagnetic phase), the electrons behave as Drude-like carriers in the whole temperature interval 5–300 K.
    Trvalý link: http://hdl.handle.net/11104/0242773