scholarly journals LOWEST ORDER CONSTRAINED VARIATIONAL CALCULATION FOR POLARIZED LIQUID 3He AT FINITE TEMPERATURE

2009 ◽  
Vol 23 (01) ◽  
pp. 113-123 ◽  
Author(s):  
G. H. BORDBAR ◽  
M. J. KARIMI ◽  
J. VAHEDI
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Variational Method ◽  
Specific Heat ◽  
Finite Temperature ◽  
Variational Calculation ◽  
Saturation Density ◽  
Energy Entropy ◽  
Spin Polarized

We have investigated some of the thermodynamic properties of spin-polarized liquid 3 He at finite temperature using the lowest order constrained variational method. For this system, the free energy, entropy and pressure are calculated for different values of the density, temperature and polarization. We have also presented the dependence of specific heat, saturation density and incompressibility on temperature and polarization.

scholarly journals Thermodynamic properties of CO 2 up to 3000 atmospheres between 25 and 150°C

1937 ◽  
Vol 160 (902) ◽  
pp. 376-384 ◽  
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Total Energy ◽  
Specific Heat ◽  
Interpolation Formula ◽  
Constant Volume ◽  
Present Communication ◽  
Different Temperatures

In previous papers (Michels and Michels 1935; Michels, Michels and Wouters 1935) the results of isotherm measurements on CO 2 and a method for interpolation of the pv values at intermediate temperatures and densities have been published. From the data obtained, the specific heat at constant volume C v , the free energy F , the total energy U , and the entropy S , have been calculated, and these results are given in the present communication. The values of F, U and S at N. T. P. have been taken as zero. The values of C v , F, S and U at a density of 1 Amagat unit ( ρ = 1) have first been calculated for different temperatures. To the values, so obtained, has been added the increase of these quantities by compression. The values of C v at ρ = 1 have been calculated, using the interpolation formula as given by Shilling and Partington (1928).

THERMODYNAMIC AND MAGNETIC PROPERTIES OF THE ARCHIMEDEAN LATTICES

2005 ◽  
Vol 19 (28) ◽  
pp. 4259-4267 ◽  
Author(s):  
Q. L. ZHANG
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Magnetic Properties ◽  
Free Energy ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Internal Energy ◽  
Type 3 ◽  
Ising Spins ◽  
Frustration Effects

We numerically study the thermodynamic properties of two Archimedean lattices1 with Ising spins using Wang–Landau algorithm of the Monte Carlo simulation. The two Archimedean lattices are of the type (3, 122) and Kagomé, for which we are particularly interested in the frustration effects. The internal energy, specific heat, free energy, entropy, magnetization and spin susceptibility are calculated.

Thermodynamic properties of underdoped YBa2Cu3O6+x cuprates for several doping values

2017 ◽  
Vol 31 (13) ◽  
pp. 1750100
Author(s):  
P. Salas ◽  
M. A. Solís ◽  
M. Fortes ◽  
F. J. Sevilla
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Cuprate Superconductors ◽  
Helmholtz Free Energy ◽  
Linear Coefficient ◽  
Quadratic Formula ◽  
Fundamental Properties ◽  
Fermion Gas ◽  
Dirac Comb

We report the thermodynamic properties of cuprate superconductors YBa2Cu3O[Formula: see text], with [Formula: see text] ranging from underdoped ([Formula: see text]) to optimally doped ([Formula: see text]) regions. We model cuprates as a boson–fermion gas mixture immersed in a layered structure, which is generated via a Dirac-comb potential applied in the perpendicular direction to the CuO2 planes, while the particles move freely in the other two directions. The optimal system parameters, namely, the planes’ impenetrability and the paired-fermion fraction, are obtained by minimizing the Helmholtz free energy in addition to fixing the critical temperature [Formula: see text] to its experimental value. Using this optimized scheme, we calculate the entropy, the Helmholtz free energy and the specific heat as functions of temperature. Additionally, some fundamental properties of the electronic specific heat are obtained, such as the normal linear coefficient [Formula: see text], the quadratic [Formula: see text] term and the jump height at [Formula: see text]. We reproduce the cubic [Formula: see text] term of the total specific heat for low temperatures. Also our multilayer model inherently brings with it the mass anisotropy observed in cuprate superconductors. Furthermore, we establish the doping value beyond which superconductivity is suppressed.

scholarly journals Thermodynamics of the Planar Hubbard Model

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3377-3380 ◽  
Author(s):  
J. Bonča ◽  
P. Prelovšek
Keyword(s):  
Thermodynamic Properties ◽  
Hubbard Model ◽  
Specific Heat ◽  
Electron Density ◽  
Finite Temperature ◽  
Lanczos Method ◽  
Two Dimensional ◽  
Phase Averaging ◽  
Half Filling ◽  
Additional Phase

The thermodynamic properties: specific heat and entropy are studied as a function of temperature and doping within the two-dimensional Hubbard model with various U/t=4-12. Quantities are calculated using the finite-temperature Lanczos method with additional phase-averaging for a system of 4×4 sites. Results show that the entropy at low T reaches a maximum near half-filling at the electron density n~1±0.15 in the whole regime of studied U/t.

Thermodynamic Properties of Natural Rubber and Isoprene

1966 ◽  
Vol 39 (1) ◽  
pp. 143-148 ◽  
Author(s):  
R. W. Warfield ◽  
M. C. Petree
Keyword(s):  
Free Energy ◽  
Glass Transition ◽  
Thermodynamic Properties ◽  
Natural Rubber ◽  
Specific Heat ◽  
Gibbs Free Energy ◽  
Kcal Mole ◽  
Specific Heat Data ◽  
Temperature Range ◽  
Heat Data

Abstract Using published specific heat data, the entropy, enthalpy, and Gibbs free energy of natural rubber (NR) have been calculated over the temperature range 0 to 320° K. The thermodynamic function Cp/T as a function of T calculated for NR exhibits a maximum at 50° K and another maximum at 210° K, which is associated with the glass transition. The number of classically vibrating units per repeating unit of NR is 6.61 at 300° K. These functions have also been calculated for isoprene over the temperature range 0 to 300° K. At 298.16° K the entropy of polymerization was found to be 24.00 cal mole−1deg−1 and the free energy of polymerization − 10.7 kcal/mole.

A Rational Equation of State for Water and Water Vapor in the Critical Region

1964 ◽  
Vol 86 (3) ◽  
pp. 320-326 ◽  
Author(s):  
E. S. Nowak
Keyword(s):  
Water Vapor ◽  
Equation Of State ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Critical Point ◽  
Critical Region ◽  
Constant Pressure ◽  
Parametric Equation ◽  
Enthalpy And Entropy ◽  
Specific Volumes

A parametric equation of state was derived for water and water vapor in the critical region from experimental P-V-T data. It is valid in that part of the critical region encompassed by pressures from 3000 to 4000 psia, specific volumes from 0.0400 to 0.1100 ft3/lb, and temperatures from 698 to 752 deg F. The equation of state satisfies all of the known conditions at the critical point. It also satisfies the conditions along certain of the boundaries which probably separate “supercritical liquid” from “supercritical vapor.” The equation of state, though quite simple in form, is probably superior to any equation heretofore derived for water and water vapor in the critical region. Specifically, the deviations between the measured and computed values of pressure in the large majority of the cases were within three parts in one thousand. This coincides approximately with the overall uncertainty in P-V-T measurements. In view of these factors, the author recommends that the equation be used to derive values for such thermodynamic properties as specific heat at constant pressure, enthalpy, and entropy in the critical region.

scholarly journals First-Principles Study of Mechanical and Thermodynamic Properties of Binary and Ternary CoX (X = W and Mo) Intermetallic Compounds

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1404
Author(s):  
Yunfei Yang ◽  
Changhao Wang ◽  
Junhao Sun ◽  
Shilei Li ◽  
Wei Liu ◽  
...  
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Gibbs Free Energy ◽  
Density Functional ◽  
Vibrational Entropy ◽  
Functional Theory ◽  
Lattice Constants ◽  
The Density Functional Theory ◽  
Ductile Behavior ◽  
Pseudo Potential

In this study, the structural, elastic, and thermodynamic properties of DO19 and L12 structured Co3X (X = W, Mo or both W and Mo) and μ structured Co7X6 were investigated using the density functional theory implemented in the pseudo-potential plane wave. The obtained lattice constants were observed to be in good agreement with the available experimental data. With respect to the calculated mechanical properties and Poisson’s ratio, the DO19-Co3X, L12-Co3X, and μ-Co7X6 compounds were noted to be mechanically stable and possessed an optimal ductile behavior; however, L12-Co3X exhibited higher strength and brittleness than DO19-Co3X. Moreover, the quasi-harmonic Debye–Grüneisen approach was confirmed to be valid in describing the temperature-dependent thermodynamic properties of the Co3X and Co7X6 compounds, including heat capacity, vibrational entropy, and Gibbs free energy. Based on the calculated Gibbs free energy of DO19-Co3X and L12-Co7X6, the phase transformation temperatures for DO19-Co3X to L12-Co7X6 were determined and obtained values were noted to match well with the experiment results.

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