Browsing by Author "Allakhverdiev, K. R."

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    Low-temperature phase transitions in TlGaS2 layer crystals
    (Pergamon Press, 1993) Aydınlı, Atilla; Ellialtioǧlu, R.; Allakhverdiev, K. R.; Ellialtioǧlu, S.; Gasanly, N. M.
    Polarized Raman scattering spectra of TlGaS2 layer crystals have been studied for the first time as a function of temperature between 8.5 and 295 K. No evidence for a soft mode behaviour has been found. The anomalies observed in the temperature dependence of low- and high-frequency phonon modes at ∼ 250 and ∼ 180 K, respectively, are explained as due to the phase transitions. It is supposed that the phase transitions are caused by the deformation of structural complexes GaS4, rather than by slippage of Tl atom channels in [110] and [110] directions, which is mainly responsible for the appearance of the low-temperature ferroelectric phase transitions in other representatives of TlBX2 layer compounds. © 1993.
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    Low-temperature photoluminescence spectra of TlInxGa1-xS2 layer mixed crystals
    (Pergamon Press, 1995) Allakhverdiev, K. R.; Gasanly, N. M.; Aydınlı, Atilla
    Low-temperature photoluminescence spectra of TlInS2, TlIn0.95Ga0.05S2 and TlIn0.8Ga0.2S2 layer crystals were studied in the temperature range 14-220 K. The temperature dependencies of bands 2.374 eV (A), 2.570 eV (E) and 2.576 eV (F) for TlInS2 are interpreted by supposing that the crystal undergoes structural phase transitions. Band A is considered to come from a donor-acceptor recombination channel. © 1995.