Sm A - ferroelectric-Sm C transition in the mixture of C7+10.O.4 and in the ferroelectric C7

Aksoy, S.
Kurt, M.
Yurtseven, Hasan Hamit
Tilt angle and the dielectric constant (susceptibility ) as functions of the field strength and temperature, respectively are calculated from the Landau phenomenological model and they are fitted to the observed data from the literature for the Sm A - Sm C* transition in the mixture of C7 + 10.O.4. Values of the critical exponents for the order parameters (tilt angle and polarization P) and tilt angle susceptibility of C7 and of the (dielectric constant) of the mixture C7 + 10.O.4 close to are extracted from the power-law formula. Our results indicate a second-order and a weakly first-order Sm A - Sm C* transitions for C7 + 10.O.4 and C7, respectively as also observed experimentally.


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First-principles calculations using density functional theory based on norm-conserving pseudopotentials have been performed to investigate the Mg adsorption on the Si(001) surface for 1/4, 1/2, and 1 monolayer (ML) coverages. For both 1/4 and 1/2 ML coverages it has been found that the most favorable site for the Mg adsorption is the cave site between two dimer rows consistent with the recent experiments. For the I ML coverage we have found that the most preferable configuration is when both Mg atoms on 2 x...
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Yurtseven, Hasan Hamit (Informa UK Limited, 2008-01-01)
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The temperature dependences of the damping constant and the relaxation time are calculated by using the Raman frequencies of a* and the lowest A(1) (TO) phonons in the ferroelectric phase close to the ferroelectric-paraelectric transition in LiTaO3 (T-C = 963 K). Both calculations are performed by considering the frequency as an order parameter for the pseudospin-phonon (PS) and the energy fluctuation (EF) models using the observed data from the literature. Values of the activation energies of this crystal ...
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Yurtseven, Hasan Hamit (Informa UK Limited, 2016-01-01)
We analyze the pressure dependence of the intensity and the frequency of a soft mode from the Raman and elastic light scattering experiments as reported in the literature close to the ferroelectric - paraelectric transition in SbSI crystal. The Raman intensity of this mode is analyzed as a function of pressure at constant temperatures of 272K (first order transition) and 234K (tricritical or second order transition) according to a power-law formula. Our analysis of the Raman intensity gives closely the mean...
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Citation Formats
S. Aksoy, M. Kurt, and H. H. Yurtseven, “Sm A - ferroelectric-Sm C transition in the mixture of C7+10.O.4 and in the ferroelectric C7,” FERROELECTRICS, pp. 21–29, 2020, Accessed: 00, 2020. [Online]. Available: