Temperature and pressure dependence of the Raman intensity and frequency of a soft mode near the tricritical point in the ferroelectric SbSI

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 field values for the order parameter. From our analysis, we also obtain that the Raman frequency (squared) of the soft mode varies linearly with the pressure at constant temperatures close to the ferroelectric - paraelectric transition in SbSI as obtained experimentally.


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The temperature dependence of the polarization P and the tilt angle theta is calculated here in the presence of a constant electric field near the smectic AC* phase transition of a ferroelectric liquid crystal using a mean field model. We demonstrate here the temperature dependence of P and theta under some fixed electric fields for the ferroelectric liquid crystal of 4-(3-methyl-2-chlorobutanoyloxy)-4'-heptyloxybiphenyl. Our predicted values of P and theta at various temperatures under fixed electric field...
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Alguel, G.; Enginer, Y.; Yurtseven, Hasan Hamit (Informa UK Limited, 2019-10-26)
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Thermally stimulated current (TSC) measurements are carried out on nominally undoped Ga4SeS3 layered semiconductor samples with the cur-rent flowing along the c-axis in the temperature range of 10 to 150 K. The results are analyzed according to various methods, such as curve fitting, initial rise and Chen's methods, which seem to be in good agreement with each other. Experimental evidence is found for the presence of three trapping centers in Ga4SeS3 with activation energies of 70, 210 and 357 meV. The calc...
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Electrical transport through CrSi2-Si Schottky junctions was studied by internal photoemission spectroscopy and electrical current-voltage (I-V) techniques in a wide temperature range. The apparent barrier height and the ideality factor derived by using thermionic emission theory were found to be strongly temperature dependent. Internal photoemission measurements yielded a weakly temperature-dependent barrier height for these samples. This difference between optical and electrical results shows that the opt...
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Yurtseven, Hasan Hamit; Sen, S. (Wiley, 2007-07-01)
We predict in this study using the mean-field theory, the phase-line equation from the free energy expanded in terms of the order parameters of solid II and III phases of NH4Cl and ND4Cl close to the X-phase transitions at high pressures. Using the temperature and pressure dependence of the coefficients given in the phase-line equation, it is shown that the experimentally observed T-P phase diagram for the solid II-solid III transition, can be predicted from the mean field model studied here for both crysta...
Citation Formats
H. H. Yurtseven, “Temperature and pressure dependence of the Raman intensity and frequency of a soft mode near the tricritical point in the ferroelectric SbSI,” FERROELECTRICS, pp. 241–249, 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40132.