Bilgilendirme: Kurulum ve veri kapsamındaki çalışmalar devam etmektedir. Göstereceğiniz anlayış için teşekkür ederiz.

Fizik Bilim Dalı

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/1819

Browse

Browsing Fizik Bilim Dalı by browse.metadata.publisher "Elsevier Science Bv"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Temperature and Excitation Intensity Tuned Photoluminescence in Ga0.75in0.25se Crystals
    (Elsevier Science Bv, 2013) Isik, M.; Guler, I.; Gasanly, N. M.
    Photoluminescence (PL) spectra of Ga0.75In0.25Se layered single crystals have been studied in the wavelength range of 580-670 nm and temperature range of 7-59 K. Two PL emission bands centered at 613 nm (2.02 eV, A-band) and 623 nm (1.99 eV, B-band) were revealed at T = 7K. The excitation laser intensity dependence of the emission bands have been studied in the 0.06-1.40 W cm(-2) range. Radiative transitions from shallow donor levels located at E-A = 0.11 and E-B = 0.15 eV below the bottom of conduction band to single shallow acceptor level located at 0.01 eV above the valence band are suggested to be responsible for the observed A- and B-bands. A simple model was proposed to interpret the recombination processes in Ga0.75In0.25Se single crystals. (c) 2012 Elsevier B.V. All rights reserved.
  • Thumbnail Image
    Article
    Citation - WoS: 10
    Citation - Scopus: 11
    Temperature Dependence of the Damping Constant and the Relaxation Time Close To the Tetragonal-Cubic Phase Transition in Srzro3
    (Elsevier Science Bv, 2017) Kiraci, A.; Yurtseven, H.
    The damping constant Gamma(sp) due to the pseudospin-phonon coupling is calculated as a function of temperature using the pseudospin-phonon coupled model and the energy fluctuation model close to the tetragonal-cubic transition (T-C = 1443 K) in SrZrO3. Using the observed Raman frequencies and the linewidth (FWHM) of the soft modes (E-g and A(1g)) from the literature, predictions of both models studied, are examined for the tetragonal-cubic transition in this crystalline system. Values of the activation energy U are extracted and also the inverse relaxation time is predicted as a function of temperature close to the phase transition studied in SrZrO3. Divergence behaviour of the damping constant (FWHM) of the soft modes is predicted from both models as also observed experimentally when T-C is approached from the tetragonal to the cubic phase in SrZrO3. The relaxation time also diverges close to the T-C in this crystal. It is indicated that the tetragonal cubic transition is of a second order as predicted from both models studied here, as also observed experimentally in SrZrO3. (C) 2016 Elsevier B.V. All rights reserved.