Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Calculation of the damping constant and the relaxation time of the LA mode in the incommensurate phase of quartz
Date
2021-04-01
Author
Ates, S.
Yurtseven, Hasan Hamit
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
141
views
0
downloads
Cite This
The damping constant (linewidth) of the LA mode is calculated as a function of temperature for the incommensurate (INC) phase of quartz by using the models of the pseudospin-phonon (PS) coupled and the energy fluctuation (EF). For this calculation, the observed linewidth (Gamma(LA)) data are used at P = 0 and 80.5MPa from the literature. Close to the incommensurate phase between the alpha and beta phases of quartz, the observed Gamma(LA) and the frequency shifts (Delta v(LA) ) are also analyzed by the power-law formula for both pressures (P = 0 and 80.5MPa). By using the Gamma(LA) and Delta v(LA), the inverse relaxation time (tau(-1)(LA)) is predicted as a function of temperature (P = 0 and 80.5MPa) in the incommensurate phase of quartz and the values of the activation energy (E-a) are deduced. Our calculated Gamma(LA) from both models (PS and EF) explain adequately the observed behavior of the linewidth of the LA mode in the incommensurate phase of quartz. Also, our predicted tau(-1)(LA) can be compared with the measurements in the INC phase of this molecular crystal.
Subject Keywords
Damping constant
,
Brillouin LA mode
,
PS and EF models
,
power-law formula
,
relaxation time
,
incommensurate phase
,
quartz
URI
https://hdl.handle.net/11511/90741
Journal
FERROELECTRICS
DOI
https://doi.org/10.1080/00150193.2021.1890460
Collections
Department of Physics, Article
Suggestions
OpenMETU
Core
Damping Constant (Linewidth) and the Relaxation Time of the Brillouin LA Mode for the Ferroelectric-Paraelectric Transition in PbZr1-xTixO3
Yurtseven, Hasan Hamit (2016-10-01)
The damping constant (linewidth) of the longitudinal acoustic (LA) mode is calculated as a function of temperature using the observed Brillouin frequencies of this mode from the literature for the ferroelectric-paraelectric transition (T-C = 657 K) in PbZr1-xTixO3 (x = 0.45). For this calculation of the damping constant, the pseudospin-phonon coupled model and the energy fluctuation model are used by fitting to the observed data for the Brillouin frequencies of the LA mode in the ferroelectric (T < T-C) and...
Calculation of the Raman and IR frequencies as order parameters and the damping constant (FWHM) close to phase transitions in methylhydrazinium structures
Kurt, M.; Yurtseven, Hasan Hamit; Kurt, A. (Elsevier BV, 2019-4)
Temperature dependences of the frequencies for the Raman modes of v (NH2), v(s) (CH3), v(1) (HCOO-), vs (CNN) and IR mode of rho (NH2) are calculated in particular, for MHyMn close to the phase transition temperature (T-C = 220 K) in the family of compounds CH3NH2NH2 M(HCOO)(3), MHyM with M = Mn, Mg, Fe and Zn. By assuming Raman and infrared frequency as an order parameter, this calculation is performed from the molecular field theory by using the experimental data from the literature. We also calculate the...
Calculation of the Dielectric Constant as a Function of Temperature Close to the Smectic A-Smectic B Transition in B5 Using the Mean Field Model
Yurtseven, Hasan Hamit (2012-01-01)
The temperature dependence of the static dielectric constant (epsilon) is calculated close to the smectic A-smectic B (S-A-S-B) transition (T-c = 71.3 degrees C) for the liquid crystal compound B5. By expanding the free energy in terms of the order parameter in the mean field theory, the expression for the dielectric susceptibility (dielectric constant) is derived and is fitted to the experimental data for epsilon which was obtained at the field strengths of 0 and 67 kV/cm from literature. Coefficients in t...
Calculation of the Damping Constant and the Relaxation Time for the Soft-Optic and Acoustic Mode in Hexagonal Barium Titanate
Yurtseven, Hasan Hamit (2012-01-01)
The temperature dependence of the damping constant is calculated below the transition temperature (T-0 = 222K) in the ferroelectric phase of hexagonal barium titanate. The damping constant of the coupled soft-optic and acoustic mode which causes an intense central peak in the light scattering spectra, is calculated using the soft mode-hard mode coupling model and the energy fluctuation model for barium titanate.
Calculation of the raman frequency, damping constant (Linewidth) and the relaxation time near the tetragonal-cubic transition in PbTiO3
KİRACI, ALİ; Yurtseven, Hasan Hamit (2017-01-01)
Frequencies, damping constants and the relaxation times of some Raman modes including the two soft modes are calculated as a function of pressure near the tetragonal-cubic transition in PbTiO3. Calculation of the Raman frequencies is performed using the observed volume data from the literature by means of the mode Gruneisen parameter at various pressures. Pressure dependence of the damping constant and the relaxation time is predicted using the pseudospin-phonon coupled model and the energy fluctuation mode...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
S. Ates and H. H. Yurtseven, “Calculation of the damping constant and the relaxation time of the LA mode in the incommensurate phase of quartz,”
FERROELECTRICS
, pp. 9–22, 2021, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/90741.