Electron–phonon contribution to electrooptical coefficient in Ca4GdO(BO3)3 single crystals
1999; Elsevier BV; Volume: 13; Issue: 3 Linguagem: Inglês
10.1016/s0925-3467(99)00078-6
ISSN1873-1252
AutoresA. Mefleh, S. Bénet, S. Brunet, H. Kaddouri, B. Sahraoui, I.V. Kityk, M. Makowska-Janusik,
Tópico(s)Glass properties and applications
ResumoElectrooptical r222 coefficient in new synthesized (Ca4GdO(BO3)3) (GdCOB) single crystals has been measured at room and liquid nitrogen temperature. To separate electronic and phonon contributions we carry out experimental measurements and theoretical calculations. To determine electronic contributions we have used experimental measurements for the SHG (λ=1.06 μm). We also measured electrooptics tensor coefficients at λ=0.694 μm as well for the IR spectral region within the 1.2–2.45 μm. From temperature dependencies within the 77–295 K we evaluate phonon harmonic and electron–phonon anharmonic contributions. Using ab initio norm-conserving pseudopotential calculations and Green function evaluations of electron–phonon contributions we estimate quantitatively electron–phonon contributions. A good agreement between the experimental and theoretical data is achieved. The presented approach can be proposed for another complex crystals in order to receive an information concerning the origin of the observed phenomena.
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