Raman Study of Solid Nitrogen in the beta Phase and Close to the Melting Line

Iseri, E. Cetinbas
Yurtseven, Hasan Hamit
This study gives the Raman frequencies calculated as functions of temperature and pressure for the lattice modes in the solid beta phase and close to the melting line (beta-fluid transition). The experimental volume data from the literature is used to calculate the Raman frequencies for the molecular nitrogen system. Some observed Raman frequencies are also used as the initial data to perform our calculations given here.


Critical Behaviour of the Heat Capacity Near the alpha-beta Phase Transition in Quartz
Yurtseven, Hasan Hamit (Walter de Gruyter GmbH, 2013-04-01)
The alpha-beta transition ( T-Q = 578 degrees C) is studied in quartz by analyzing the experimental heat capacity C-p data taken from the literature, using a power-law formula. Values of the critical exponent alpha for C-p are extracted below and above T-Q, which describe the alpha-beta transition as a second order transition in quartz. The alpha values obtained here are compared with the predictions of the theoretical models.
Calculation of the Specific Heat Close to Phase Transition in S-triazine
KURT, MUSTAFA; Yurtseven, Hasan Hamit (Walter de Gruyter GmbH, 2009-01-01)
The specific heat C-V as a function of temperature has been calculated using the quasi-harmonic and mean field approximation for s-triazine close to the transition temperature (T-C=198 K). Using the parameters for the shear strain angle (order parameter) fitted to the observed Raman frequencies of the four bands, the specific heat C-V is calculated from the free energy of s-triazine.
Calculation of molar volume as a function of temperature close to the melting point in benzene
Yurtseven, Hasan Hamit (Walter de Gruyter GmbH, 2007-01-01)
We study here the temperature dependence of the molar volume for constant pressures in benzene close to the melting point. By analyzing the experimental data for the thermal expansivity at various pressures in benzene, we calculate the molar volumes as functions of temperature in this system. Our calculations show that discontinuities in the molar volume decrease as the melting temperatures increase along the melting line when the constant pressures vary from 70.5 MPa to 175.2 MPa, as also observed experime...
Yurtseven, Hasan Hamit (1982-01-01)
The Raman spectrum of NH4Cl has been studied as a function of temperature and pressure close to the multicritical point at which the λ-transition changes from first to second order. Variations in the intensities of appropriate bands have been used to calculate the critical exponents for the order parameter. By varying the temperature at fixed pressures of zero, 3.0 k bar and 1.5 k bar, exponent values of β = 0.154 ± 0.012, β = 0.33 ± 0.06 and β = 0.26 ± 0.06 have been obtained for the first-order, second-or...
Calculation of the Raman Linewidths of Lattice Modes Close to the alpha-beta Transition in Quartz
Lider, Mustafa Cem; Yurtseven, Hasan Hamit (Walter de Gruyter GmbH, 2012-12-01)
The Raman frequencies of the lattice modes (147 cm(-1) and 207 cm(-1)) are analyzed for the alpha-beta 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.
Citation Formats
E. C. Iseri and H. H. Yurtseven, “Raman Study of Solid Nitrogen in the beta Phase and Close to the Melting Line,” HIGH TEMPERATURE MATERIALS AND PROCESSES, pp. 25–31, 2013, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40322.