Similarity in statistical thermodynamics. V. Approximate calculations of temperature dependences of thermodynamic properties for complex gaseous molecules

1967 ◽  
Vol 32 (1) ◽  
pp. 219-234
Author(s):  
Č. Černý
Keyword(s):  
Thermodynamic Properties ◽  
Statistical Thermodynamics ◽  
Temperature Dependences

Transport and Thermodynamic Properties of CeRu2Al10 Controlled by Pressure at around Critical Pressure

2018 ◽  
Vol 941 ◽  
pp. 1378-1383 ◽  
Author(s):  
Yukihiro Kawamura ◽  
Chihiro Sekine ◽  
Kazuyuki Matsubayashi ◽  
Yoshiya Uwatoko ◽  
Takashi Nishioka
Keyword(s):  
Electrical Resistivity ◽  
High Temperature ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Joule Heating ◽  
Ground State ◽  
Critical Pressure ◽  
Antiferromagnetic Ordering ◽  
Temperature Dependences

We present transport and thermodynamic properties of CeRu2Al10 controlled by pressure in a vicinity of a critical pressure PC ~ 4GPa, where antiferromagnetic ordering disappears. The resistivity under pressure was measured with DC four terminal method and the AC specific heat under pressure was measured by Joule heating type technique. The pressure was applied by cubic-anvil-apparatus and palm-cubic-anvil-apparatus. The results of AC specific heat indicate TN holds at high temperature up to 3.9 GPa but suddenly disappears above this pressure. We confirmed TN from thermodynamic properties. Although CeRu2Al10 is in a Kondo semiconducting ground state at 4 GPa, temperature dependences of electrical resistivity at 4.6 GPa and 5.9 GPa indicate metallic ground state in these pressures. CeRu2Al10 does not show superconductivity down to 0.7 K at 4.6 GPa and 5.9 GPa.

First-Principles Investigation of Phase Stability, Elastic and Thermodynamic Properties in L12 Co3(Al,Mo,Ta) Phase

2017 ◽  
Vol 898 ◽  
pp. 438-445
Author(s):  
Qiang Yao ◽  
Tong Lu ◽  
Qiong Wang ◽  
Yan Wang ◽  
Yu Hong Zhu
Keyword(s):  
Thermodynamic Properties ◽  
Phase Stability ◽  
First Principles ◽  
Linear Thermal Expansion ◽  
Temperature Dependent ◽  
Shear Moduli ◽  
Young’S Moduli ◽  
High Temperature Alloys ◽  
Temperature Dependences ◽  
Significant Temperature

First-principles calculations have been performed to investigate the phase stability, elastic, and thermodynamic properties of Co3(Al,Mo,Ta) with the L12 structure. Calculated elastic constants showed that Co3(Al,Mo,Ta) is mechanically stable and possesses intrinsic ductility. Young’s and shear moduli of polycrystalline Co3(Al,Mo,Ta) were calculated using the Voigt-Reuss-Hill approach. It was found that the shear and Young’s moduli of Co3(Al,Mo,Ta) were smaller than those of Co3(Al,W). States density indicated the existence of covalent-like bonding in Co3(Al,Mo,Ta). Temperature-dependent thermodynamic properties of Co3(Al,Mo,Ta) could be described satisfactorily using the Debye-Grüneisen approach, including entropy, enthalpy, heat capacity and linear thermal expansion coefficient, showing their significant temperature dependences. Furthermore the obtained data could be employed in the modeling of thermodynamic and mechanical properties of Co-based alloys to enable the design of high temperature alloys.

scholarly journals SYNTHESIS AND STUDY OF THERMODYNAMIC PROPERTIES OF NEW ZINCATE-MANGANITES NdM2IIZnMnO6 (MII − Mg, Ca)

2018 ◽  
Vol 61 (3) ◽  
pp. 16
Author(s):  
Bulat К. Kasenov ◽  
Shuga B. Kasenova ◽  
Zhenisgul I. Sagintaeva ◽  
Yerbolat Y. Kuanyshbekov ◽  
Meruert O. Turtubaeva
Keyword(s):  
Heat Capacity ◽  
Phase Transitions ◽  
Thermodynamic Properties ◽  
Temperature Dependence ◽  
Ceramic Technology ◽  
Cell Parameters ◽  
Dynamic Calorimetry ◽  
Temperature Dependences ◽  
Calorimetric Studies ◽  
Experimental Values

Zincate-manganites with the composition NdM2IIZnMnO6 (MII− Mg, Ca) were synthesized using ceramic technology from oxides of Nd (III), Zn (II), Mn (III) and carbonates of alkaline-earth metals - magnesium and calcium. X-ray patterns of the prepared substancies were measured on a DRON-2.0 diffractometer. We established that they crystallize in the cubic system with the following unit cell parameters: NdMg2ZnMnO6 – а=13.927±0.035 Å, Z = 4, V0 = 2701.36±0.11 Å3, V0el.cell. = 675.34±0.03 Å3, ρX-ray = 4.20, ρpycn. = 4.19±0.01 g/cm3; NdCa2ZnMnO6 – а=13.910±0.030 Å, Z = 4, V0 = 2691.45±0.10 Å3, V0el.cell. = 672.86±0.03 Å3, ρX-ray = 4.04, ρpycn. = 4.01±0.08 g/сm3. The temperature dependence of the heat capacity of NdMg2ZnMnO6 and NdCa2ZnMnO6 was studied by dynamic calorimetry in the range of 298.15-673 K on the IT-S-400 calorimeter. Five parallel experiments were performed at each temperature point with 25 K step. The results were averaged and analyzed using mathematical statistics. As a result of calorimetric studies of the heat capacity, within the temperature range of 298.15-673 K, we discovered on the curves of the temperature dependence of heat capacity the phase transitions of the II kind at the following temperatures: 373, 548 К- NdMg2ZnMnO6, 448, 573 К – NdCa2ZnMnO6. These phase transitions were probably due to Schottky effects -the transition from semiconductivity to metallic conductivity, and variations in capacity, dielectric permittivity, the occurrence of Curie or Neel points. The equations of the temperature dependence of the heat capacity were derived on the basis of the experimental values with account the temperatures of the phase transitions. By the ion increment method, we calculated the standard entropies of the compounds investigated. We calculated the temperature dependences of С°р(Т) and thermodynamic functions Н°(Т)-Н°(298.15), S°(T) and Фхх(Т).Forcitation:Kasenov B.K., Kasenova Sh.B., Sagintaeva Zh.I., Kuanyshbekov Е.Е., Turtubaeva М.О. Synthesis and study of thermodynamic properties of new zincate-manganites NdM2IIZnMnO6 (MII − Mg, Ca). Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 3. P. 16-20

Introduction to statistical thermodynamics of condensed matter

2005 ◽  
Author(s):  
Boris S. Bokstein ◽  
Mikhail I. Mendelev ◽  
David J. Srolovitz
Keyword(s):  
Thermodynamic Properties ◽  
Intermolecular Interactions ◽  
Disordered Systems ◽  
Condensed Matter ◽  
Thermodynamic Description ◽  
Statistical Thermodynamics ◽  
Ideal Gas ◽  
The Other ◽  
Particle Correlation ◽  
The Ideal

In this Chapter we apply statistical thermodynamics to condensed matter. We start with a description of the structure of liquids and the relation between this structure and its thermodynamic properties. Taking the low density limit, we derive a general equation of state appropriate for both liquids and gases. Next, we turn to a statistical thermodynamic description of solids. Finally, we consider the statistical theory of solutions. Recall that interactions between molecules in an ideal gas can be ignored for the purpose of determining thermodynamic properties. Therefore, we can assume that the spatial position of a molecule is independent of the positions of all of the other molecules in the gas. In real gases under high pressure and, even more so, in condensed matter, the intermolecular interactions play an important role and the positions of molecules are not independent. In other words, intermolecular interactions lead to the formation of correlations in the location of the molecules or, equivalently, to the development of structure. The energy of the system and the other thermodynamic properties depend on this structure. Therefore, we now turn to a discussion of structure. There are two distinct approaches to this problem. The first approach is designed for crystalline materials and is based upon a description of crystal symmetry. The description of this method is outside the scope of this text. The second is based upon the introduction of probability functions for atom locations and is applicable to disordered systems such as dense gases, liquids, and amorphous solids. Consider, as we are apt to do, the ideal gas. In this case, the probability of finding s molecules at points r1, r2, . . . , rs is simply In contrast with the ideal gas, the positions of molecules in high density gases or condensed matter are not independent of each other. Therefore, we write where Fs(r1, . . . , rs) is called the s-particle correlation function. Note three obvious properties of such functions. First, the system does not change when we exchange two molecules. This implies that the correlation functions should be symmetric with respect to their arguments.

THERMODYNAMIC PROPERTIES OF MC (M = V, Nb, Ta): FIRST-PRINCIPLES CALCULATIONS

2013 ◽  
Vol 27 (19) ◽  
pp. 1341035 ◽  
Author(s):  
YONG CAO ◽  
JINGCHUAN ZHU ◽  
YONG LIU ◽  
ZHISHEN LONG
Keyword(s):  
Experimental Data ◽  
Heat Capacity ◽  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
First Principles ◽  
Linear Expansion ◽  
Debye Model ◽  
Linear Expansion Coefficient ◽  
First Principles Calculations ◽  
Temperature Dependences

Through the quasi-harmonic Debye model, the pressure and temperature dependences of linear expansion coefficient, bulk modulus, Debye temperature and heat capacity have been investigated. The calculated thermodynamic properties were compared with experimental data and satisfactory agreement is reached.

scholarly journals The calculation of specific heats for some important solid components in hydrogen production process based on CuCl cycle

2014 ◽  
Vol 18 (3) ◽  
pp. 823-831 ◽  
Author(s):  
Jurij Avsec
Keyword(s):  
Mathematical Model ◽  
Hydrogen Production ◽  
Thermodynamic Properties ◽  
Large Scale ◽  
Solid Phase ◽  
Statistical Thermodynamics ◽  
Thermochemical Cycle ◽  
Direct Production ◽  
Production Of Hydrogen ◽  
The Mathematical Model

Hydrogen is one of the most promising energy sources of the future enabling direct production of power and heat in fuel cells, hydrogen engines or furnaces with hydrogen burners. One of the last remainder problems in hydrogen technology is how to produce a sufficient amount of cheap hydrogen. One of the best options is large scale thermochemical production of hydrogen in combination with nuclear power plant. copper-chlorine (CuCl) cycle is the most promissible thermochemical cycle to produce cheap hydrogen.This paper focuses on a CuCl cycle, and the describes the models how to calculate thermodynamic properties. Unfortunately, for many components in CuCl cycle the thermochemical functions of state have never been measured. This is the reason that we have tried to calculate some very important thermophysical properties. This paper discusses the mathematical model for computing the thermodynamic properties for pure substances and their mixtures such as CuCl, HCl, Cu2OCl2 important in CuCl hydrogen production in their fluid and solid phase with an aid of statistical thermodynamics. For the solid phase, we have developed the mathematical model for the calculation of thermodynamic properties for polyatomic crystals. In this way, we have used Debye functions and Einstein function for acoustical modes and optical modes of vibrations to take into account vibration of atoms. The influence of intermolecular energy we have solved on the basis of Murnaghan equation of state and statistical thermodynamics.

scholarly journals Statistical thermodynamics of mixtures with zero energies of mixing

1944 ◽  
Vol 183 (993) ◽  
pp. 203-212 ◽  
Keyword(s):  
Thermodynamic Properties ◽  
General Formula ◽  
Statistical Thermodynamics ◽  
Raoult’S Law ◽  
Geometric Properties ◽  
Different Types ◽  
Thermodynamics Of Mixtures ◽  
Raoult's Law

A general formula has been obtained for the number of distinct arrangements of a mixture of any number of different types of molecules each with its own geometric properties. From this are deduced the thermodynamic properties of such mixtures when the energies of mixing are zero. In particular, the generalization of Raoult’s law has been obtained. The technique used is considerably simpler than that previously applied to problems of this type.

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