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
Analysis of the Raman frequencies of a lattice mode in NH4Cl close to the tricritical and second order phase transitions
Date
2006-4
Author
Yurtseven, Hasan Hamit
Metadata
Show full item record
Item Usage Stats
299
views
0
downloads
Cite This
We analyze here our observed Raman frequencies of the nu(5) (174 cm(-1)) mode in NH4Cl close to its tricritical (P = 1.6 kbar) and the second order (P = 2.8 kbar) phase transitions. The critical behavior of the frequency shifts 1/nu (partial derivative nu/partial derivative T)(P) for this optical mode is described by a power-law with the critical exponent a. Our values of a = 0.01 (T < T-C) and a = 0.11 (T > T-C) for P = 1.6 kbar in NH4Cl are close to the values of 0.066 (=1/16) below T-C and 0.125 (=1/8) above T-C for the specific heat C-P due to a three-dimensional Ising model. Our value of a = 0. 18 (T < T-C) for P = 2.8 kbar in NH4Cl is also close to the Ising value (1/16), whereas our value of a = 0.64 (T > T-C) is far from the Ising value (1/8), which can be reasonably compared with those obtained by previous workers, for the thermal expansivity alpha(P) and the specific heat C-P in this crystalline system.
Subject Keywords
Raman frequencies
,
Lattice mode
,
NH4Cl
URI
https://hdl.handle.net/11511/28611
Journal
Chemical Physics
DOI
https://doi.org/10.1016/j.chemphys.2005.10.015
Collections
Department of Physics, Article
Suggestions
OpenMETU
Core
Analysis of the frequency shifts close to the second order phase transition in NH4Cl
Yurtseven, Hasan Hamit (2001-03-01)
In this study we analyzed observed Raman data for the frequencies of the disorder-induced modes of v(7) (93 cm(-1)) and vs (144 cm(-1)) in the second order phase region of NH4Cl (P = 2.8 kbar). By means of a power-law formula describing the critical behaviour of the frequency shifts 1/v(partial derivativev/partial derivativeT)p for those phonon modes studied, we extract the critical exponent value of a = 0.25, which can also describe the critical behaviour of the specific hear Cp close to the second order p...
Calculation of the soft mode frequency for the alpha beta transition in quartz
Yurtseven, Hasan Hamit (null; 2015-09-18)
The Raman frequencies of the lattice modes (147 cm-1 and 207 cm-1 are analyzed for the α-β transition in quartz according to a power-law formula with the critical exponent by using the experimental data. The temperature dependence of the Raman frequency is associated with the order parameter (polarization P) for this transition in the quartz crystal. The damping constant of the lattice modes studied here is calculated using the Raman frequencies at various temperatures for the α-β transition in quartz (Tc =...
Analysis of the Raman frequency as an order parameter close to the melting point in biphenyl
Yurtseven, Hasan Hamit (2017-05-01)
We analyze the observed Raman frequencies of the three lattice modes (modes A, B and 70cm-1) near the melting point in biphenyl by calculating the temperature dependence of the order parameter from the mean field theory. This is based on the correlation between the frequency and the order parameter close to the melting temperature (Tm=343K) in biphenyl. The Raman frequencies of the modes A and B decrease rapidly as the melting temperature is approached, whereas the Raman frequency of the 70 cm-1 is smoothly...
Calculation of the Raman frequencies as a function of temperature in phase I of benzene
Tari, O.; Yurtseven, Hasan Hamit (2013-06-01)
This study gives our calculation of the Raman frequencies of the lattice modes A (A(1g)), B (A(g)B(2g)) and C (B1gB3g) as a function of temperature at constant pressures of 0, 1.4 and 3.05 GPa for the solid phase I of benzene. The Raman frequencies of those lattice modes are calculated using the volume data from the literature through the mode Gruneisen parameters for the solid phase I of this molecular crystal. It is shown here that the Raman frequencies of the lattice modes studied decrease with increasin...
Calculation of the Raman frequency as a function of pressure for the phases of I, III, IV and V in cyclohexane
Yurtseven, Hasan Hamit (2014-06-05)
The Raman frequencies of the v(5) mode are calculated as a function of pressure up to 10 GPa (room temperature) for the phases I, III, IV and V of cyclohexane using the volume data from the literature by means of the isothermal mode Griineisen parameter gamma(T) of this mode.
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
H. H. Yurtseven, “Analysis of the Raman frequencies of a lattice mode in NH4Cl close to the tricritical and second order phase transitions,”
Chemical Physics
, pp. 574–578, 2006, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/28611.