Temperature Dependence of The Raman Frequency Shifts Related to The Specific Heat and Thermal Expansion Close To I-II Phase Transition in S-Triazine.

AbstractThe thermodynamic quantities of the isothermal compressibility, thermal expansion and the specific heat are calculated here as a function of pressure by using the observed Raman frequencies of the lattice modes and vibrons in the η phase of solid nitrogen. The Pippard relations and their spectroscopic modifications are constructed, and the slope dP/dT is deduced from the Raman frequency shifts in this phase of N2. It is shown that the thermodynamic quantities can be predicted from the Raman frequency shifts, in particular, in the η phase of solid nitrogen.

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Specific heat calculated from the Raman frequency shifts close to the alpha phase transition in NH4Br

High Temperatures-High Pressures ◽

10.1068/htjr070 ◽

2003 ◽

Vol 35/36 (3) ◽

pp. 321-327

Author(s):

Hamit Yurtseven ◽

Askin Yanik

Keyword(s):

Phase Transition ◽

Specific Heat ◽

Alpha Phase ◽

Raman Frequency ◽

Frequency Shifts

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THERMODYNAMIC QUANTITIES AT HIGH PRESSURES IN THE i AND θ PHASES OF SOLID NITROGEN DEDUCED BY RAMAN FREQUENCY SHIFTS FOR THE INTERNAL MODES IN LITERATURE

International Journal of Modern Physics B ◽

10.1142/s0217979213500355 ◽

2013 ◽

Vol 27 (09) ◽

pp. 1350035 ◽

Cited By ~ 5

Author(s):

H. YURTSEVEN ◽

S. SARITAŞ

Keyword(s):

Experimental Data ◽

Thermal Expansion ◽

Specific Heat ◽

Pressure Dependence ◽

Isothermal Compressibility ◽

High Pressures ◽

Raman Frequency ◽

Thermodynamic Quantities ◽

Frequency Shifts ◽

Solid Nitrogen

The pressure dependence of the Raman frequencies of the internal modes is analyzed (T = 300 K ) for the phases i and θ of solid nitrogen using the experimental data from the literature. Through the mode Grüneisen parameter, the isothermal compressibility κT, thermal expansion αp and the specific heat Cp–Cv are calculated as a function of pressure using the Raman data in these phases. We obtain that the αp varies linearly with the (1/υ)(∂υ/∂P)T and also that the Cp–Cv varies linearly with the αp for N 2. Our results show that by means of the analysis given here, the αp, κT and Cp–Cv can be predicted from the Raman frequency shifts for the i and θ phases of solid nitrogen.

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PIPPARD RELATIONS MODIFIED FOR THE RAMAN FREQUENCY SHIFTS CLOSE TO I–II PHASE TRANSITION IN S-TRIAZINE

International Journal of Modern Physics B ◽

10.1142/s0217979211059553 ◽

2011 ◽

Vol 25 (32) ◽

pp. 4641-4653

Author(s):

H. YURTSEVEN ◽

M. KURT

Keyword(s):

Phase Transition ◽

Specific Heat ◽

Pressure Dependence ◽

Isothermal Compressibility ◽

Raman Frequency ◽

Experimental Measurements ◽

Frequency Shifts ◽

Raman Modes

The pressure dependence of the frequency shifts 1/ω(∂ω/∂T)P is calculated from the 1/ω(∂ω/∂P)T for the Raman modes I and IV according to the spectroscopic modifications of the Pippard relations. The observed Raman frequencies of those modes are used for this calculation close to the I–II phase transition in s-triazine. From the frequency shifts, the isothermal compressibility κT and the specific heat CP are also calculated as a function of pressure close to the I–II phase transition in s-triazine. Our calculated values of 1/ω(∂ω/∂T)P κT and CP can be compared with the experimental measurements at various pressures in the phases I and II of s-triazine.

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Теплоемкость и тепловое расширение нанокомпозитов триглицинсульфат-пористое стекло

Физика твердого тела ◽

10.21883/ftt.2018.07.46118.027 ◽

2018 ◽

Vol 60 (7) ◽

pp. 1328

Author(s):

Е.А. Михалева ◽

И.Н. Флёров ◽

А.В. Карташев ◽

М.В. Горев ◽

Л.Н. Коротков ◽

...

Keyword(s):

Phase Transition ◽

Thermal Expansion ◽

Specific Heat ◽

Glass Matrix ◽

Pore Diameter ◽

Pressure Coefficient ◽

Minor Effect ◽

Restricted Geometry ◽

Glass Composites ◽

M Phase

AbstractThe effect of restricted geometry on specific heat capacity and thermal expansion of the triglycine sulfate (TGS)–borosilicate glass composites have been studied first. A decrease in the entropy and temperature of the P 2_1 ↔ P 2_1/ m phase transition in the TGS component with decreasing the glass matrix pore diameter at the invariable specific heat and thermal expansion coefficient has been observed. The estimates are indicative of the minor effect of internal pressure on the TGS pressure coefficient dT _ C / dp in the composites.

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