Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article Calculation of the Halfwidth and the Activation Energy for the Soft Raman Modes in the Brominated Compounds of Tris-Sarcosine Calcium Chloride(Walailak University, 2022) Kiraci, A.This letter contributes how to calculate the anomalous behavior for the damping constant (halfwidth) of the ferroelectric Tris-Sarcosine Calcium Chloride (TSSC) and its brominated compounds TSSC1−xBrx (x = 0.13, 0.42 and 0.60) from the wavenumber data of the soft modes below the phase transition temperature of TC. The pseudospin-phonon coupled (PS) and the energy fluctuation (EF) models derived from the dynamical Ising model were used. Both PS and EF models have been used to contribute understanding the temperature dependence of the phase transition mechanism of TSSC1−xBrx. In addition, values of the activation energy for TSSC1−xBrx (x = 0, 0.13, 0.42 and 0.60) were extracted from the damping constant as calculated from both models (PS and EF). Our results indicate order-disorder type phase transition for TSSC1−xBrx. © 2022, Walailak University. All rights reserved.Article Raman Wavenumbers Calculated as a Function of Pressure From the Mode Gruneisen Parameter of Pzt (X = 0.48) Ceramic Close To the Monoclinic-Cubic Transition(World Scientific Publ Co Pte Ltd, 2019) Kiraci, A.The isothermal mode Gruneisen parameter gamma(T)(P) of some Raman modes in PbZr1-xTixO3 (PZT, x = 0.48) were calculated as a function of pressure by means of the observed pressure-dependent volume data of PZT (x = 0.48) crystal from the literature at room temperature of 298 K. Those calculated values of gamma(T)(P) were then used to compute the pressure dependence of the Raman modes in PZT (x = 0.48) ceramic studied here. The observed and calculated values of the Raman wavenumbers in PZT were in good agreement, which indicates that the isothermal mode Gruneisen parameter can also be used to predict the pressure-dependent wavenumbers of some other perovskite-type crystals. Additionally, the pressure dependence of the thermodynamic quantities such as isothermal compressibility kappa(T), thermal expansion alpha(P) and the specific heat C-P - C-V of PZT (x = 0.48) ceramic were predicted at constant temperature of 298 K. Here, the experimentally measurable thermodynamic quantities calculated for PZT (x = 0.48) ceramics provide theoretically a significant opportunity for testing.