Pressure dependence of the Raman frequencies of ammonia solid I near the melting point

We calculated in this study the Raman frequencies of some lattice modes in the melting region of ammonia solid I. The Raman frequencies of those phonon modes were obtained through the Gruneisen relation using the volume data for the ammonia solid I from the literature. Our calculated Raman frequencies require for comparison the experimental Raman frequencies measured as a function of pressure for some fixed temperatures in the ammonia solid I.


Calculation of the Raman frequencies of lattice modes in the disordered phase II of NH4Br at high pressures
Yurtseven, Hasan Hamit (Physics Essays Publication, 2010-01-01)
The Raman frequencies are calculated here at various temperatures for the nu(7) (56 cm(-1)) and nu(5) (134 cm(-1)) lattice modes in the disordered phase II of NH4Br. The lattice parameter data obtained at zero pressure are used to calculate the Raman frequencies of those modes studied for constant pressures of 0.1, 108, and 637.5 MPa in phase II of the NH4Br crystal. Through the mode Gruumlneisen parameter which is kept constant in the disordered phase II, the Raman frequencies calculated decrease linearly ...
Analysis of the orientational order parameter and the magnetic field as functions of temperature for p-anisaldazine
Yurtseven, Hasan Hamit (Korean Physical Society, 2016-06-01)
We analyze in this study the orientational order parameter and the magnetic field as functions of temperature close to the nematic-isotropic liquid (NI) transition in anisaldazine. The experimental data from the literature are analyzed by using a power-law formula for both the orientational order parameter and the magnetic field, and the critical exponents are deduced. In particular, the mean field value of beta = 0.5 for the critical exponent of the orientational order parameter is used, and the power-law ...
Temperature dependence of the first-order Raman phonon lines in GaS0.25Se0.75 layered crystals
Hasanlı, Nızamı (Institute of Physics, Polish Academy of Sciences, 2002-12-01)
Systematic measurements by Raman scattering. of the frequency and line width of the zone-center optical modes in GaS0.25Se0.75 layered crystal over the temperature, range of 10-300 K are carried out. The analysis of-temperature dependence of intralayer modes shows that frequency shift and line broadening are successfully modeled by including the contributions from thermal expansion and lattice anharmonicity. The purely anharmonic contribution (phonon-phonon coupling) is found to be due to three-phonon proce...
Eigensolution, expectation values and thermodynamic properties of the screened Kratzer potential
Ikot, A. N.; Okorie, U. S.; Sever, Ramazan; Rampho, G. J. (Springer Science and Business Media LLC, 2019-08-12)
Within the framework of non-relativistic quantum mechanics via the Nikiforov-Uvarov (NU) method, we obtained the energy eigenvalues and the corresponding normalized eigenfunctions of a newly proposed screened Kratzer potential for lithium hydride (LiH) and hydrogen chloride (HCl) diatomic molecules. With the help of the Hellman-Feynman theorem, the expressions for the expectation values of the square of inverse of position, r(-2), inverse of position, r(-1), kinetic energy, T, and square of momentum, p(2), ...
Trap distribution in TlInS2 layered crystals from thermally stimulated current measurements
IŞIK, MEHMET; Goksen, K.; Hasanlı, Nızamı; Ozkan, H. (Korean Physical Society, 2008-02-01)
We have carried out thermally stimulated current (TSC) measurements with the current flowing along the layer on as-grown TlInS2 layered single crystals in the low temperature range 10 - 110 K with different heating rates of 0.1 - 1.5 K/s. Experimental evidence was found for the presence of two shallow electron trapping centers with activation energies of 12 and 14 meV. Their capture cross sections have been determined as 2.2 x 10(-23) and 7.1 x 10(-25) cm(2), respectively. It was concluded that retrapping i...
Citation Formats
H. H. Yurtseven, “Pressure dependence of the Raman frequencies of ammonia solid I near the melting point,” ACTA PHYSICA POLONICA A, pp. 557–564, 2001, Accessed: 00, 2020. [Online]. Available: