Estimation of thermodynamical quantities of tin chalcogenides from spectroscopic data

725-729Statistical thermodynamics and spectroscopy have been combined to evaluate thermodynamical quantities of tin chalcogenides (SnO, SnS, SnSe and SnTe). Their temperature dependence has been studied in the temperature range 100-2200K. The authenticity of data is established by the comparison of reported values. Discrepancies between calculated values and observed values can mainly be attributed to contributions from excited electronic states

NEW BAND SYSTEMS OF YbF MOLECULE IN THERMAL EMISSION

Author Institution: Saha's Spectroscopy Laboratory, Department of Physics, University of Allahabad, Allahabad (U.P.), IndiaThermally excited spectrum of the Ytterbium monofluoride (YbF) molecule has been examined in the spectral region 4500-5900 \AA\ at a reciprocal linear dispersion of 3.7 \AA/mm using high temperature vacuum graphite furnace at 2000 $^irc$C and two meter Plane Grating Spectrograph (PGS-2). A total of 205 single and double headed, violet degraded bands have been recorded, out of which 121 are new. The observed bands have been classified into already reported systems and one entirely new system. The vibrational analyses performed suggest that the systems arise from ground state $^2\Sigma$. The following vibrational constants have been from the analyses: \vspace{1em} \begin{tabular}{ccccccc} System &Region &$\omega_e^{\prime}$&$\omega_e^{\prime}x_e^\prime$&$\omega_e^{\prime\prime}$&$\omega_e^{\prime\prime}x_e^{\prime\prime}$& $\nu_{00}$ \\ A-X& $\lambda\lambda$5250 - 5900 \AA & 528.0& 2.00& 506.0& 1.90& 18105.0\\ B$_1$-X& $\lambda\lambda$4800 - 5300 \AA & 531.4& 2.70& 504.0& 2.60& 19450.0\\ B$_1^\prime$-X& $\lambda\lambda$4800 - 5300 \AA & 544.0& 3.85& 505.5& 1.90& 19468.0\\ B$_1$-X& $\lambda\lambda$4300 - 4900 \AA & 526.0& 2.60& 505.5& 1.90& 21073.0 \end{tabular

THERMODYNAMIC QUANTITIES OF CARBON NANOTUBES FROM SPECTROSCOPIC DATA

Author Institution: Saha's Spectroscopy Laboratory, Department of Physics, University of Allahabad, Allahabad (U.P.), IndiaThermodynamical quantities like Free Energy, Enthalpy, Entropy and Specific heat of Carbon nanotubes have been calculated from spectroscopic data using partition theory. The results have been calculated in the temperature range 50-2150 K. The plot of the variation of the heat capacity with temperature have been studied and obtained results have been discussed in the light of spectroscopic data