Journal articles: 'Thermodynamic phase'

1

Haldar, Amritendu, and Ritabrata Biswas. "Thermodynamics of d-dimensional charged AdS (Anti-de sitter) black holes: Hamiltonian approach and Clapeyron equation." Modern Physics Letters A 34, no. 22 (July 20, 2019): 1950170. http://dx.doi.org/10.1142/s0217732319501700.

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The study of thermodynamics in the view of the Hamiltonian approach is the newest tool to analyze the thermodynamic properties of the black holes (BHs). In this paper, we investigate the thermodynamics of d-dimensional [Formula: see text] asymptotically Anti-de Sitter (AdS) BHs. A thermodynamic representation based on symplectic geometry is introduced in this paper. We extend the thermodynamics of d-dimensional charged AdS BHs in the views of a Hamiltonian approach. Firstly, we study the thermodynamics in reduced phase space and correlate with the Schwarzschild solution. Then we enhance it in the extended phase space. In an extended phase space, the thermodynamic equations of state are stated as constraints. We apply the canonical transformation to analyze the thermodynamics of the said type of BHs. We plot [Formula: see text]-[Formula: see text] diagrams for different dimensions d taking the temperatures [Formula: see text], [Formula: see text] and [Formula: see text] and analyze the natures of the graphs and the dependences on d. In these diagrams, we point out the regions of coexistence. We also examine the phase transition by applying “Maxwell’s equal area law” of the said BHs. Here, we find the regions of coexistence of two phases which are also depicted graphically. Finally, we derive the “Clapeyron equation” and investigate the latent heat of isothermal phase transition.

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Li, Xiao Bo, and Ping Zhang. "Phase Stability of Nb-Mo Alloys." Advanced Materials Research 266 (June 2011): 288–91. http://dx.doi.org/10.4028/www.scientific.net/amr.266.288.

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The characteristic crystal model is applied to the study of phase stability and thermodynamics in substitutional bcc-based Nb-Mo alloys. The basic principle and method of alloy thermodynamics which is described by the characteristic crystal model is introduced in detail. The thermodynamic properties of the Nb-Mo system are evaluated to describe the Gibbs energies of various phases including both disordered and ordered phases. The phase diagram of Nb-Mo is assessed and predicted. The results are in good agreement with experiments. An unambiguous tendency toward order with a B2 superstructure in a broad range of alloy composition is predicted.

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Kvamme, Bjørn, Jinzhou Zhao, Na Wei, Wantong Sun, Navid Saeidi, Jun Pei, and Tatiana Kuznetsova. "Hydrate Production Philosophy and Thermodynamic Calculations." Energies 13, no. 3 (February 4, 2020): 672. http://dx.doi.org/10.3390/en13030672.

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The amount of energy in the form of natural gas hydrates is huge and likely substantially more than twice the amount of worldwide conventional fossil fuel. Various ways to produce these hydrates have been proposed over the latest five decades. Most of these hydrate production methods have been based on evaluation of hydrate stability limits rather than thermodynamic consideration and calculations. Typical examples are pressure reduction and thermal stimulation. In this work we discuss some of these proposed methods and use residual thermodynamics for all phases, including the hydrate phase, to evaluate free energy changes related to the changes in independent thermodynamic variables. Pressures, temperatures and composition of all relevant phases which participate in hydrate phase transitions are independent thermodynamic variables. Chemical potential and free energies are thermodynamic responses that determine whether the desired phase transitions are feasible or not. The associated heat needed is related to the first law of thermodynamics and enthalpies. It is argued that the pressure reduction method may not be feasible since the possible thermal gradients from the surroundings are basically low temperature heat that is unable to break water hydrogen bonds in the hydrate–water interface efficiently. Injecting carbon dioxide, on the other hand, leads to formation of new hydrate which generates excess heat compared to the enthalpy needed to dissociate the in situ CH4 hydrate. But the rapid formation of new CO2 hydrate that can block the pores, and also the low permeability of pure CO2 in aquifers, are motivations for adding N2. Optimum mole fractions of N2 based on thermodynamic considerations are discussed. On average, less than 30 mole% N2 can be efficient and feasible. Thermal stimulation using steam or hot water is not economically feasible. Adding massive amounts of methanol or other thermodynamic inhibitors is also technically efficient but far from economically feasible.

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Guo, Xiongying, Huaifan Li, Lichun Zhang, and Ren Zhao. "The Phase Transition of Higher Dimensional Charged Black Holes." Advances in High Energy Physics 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/7831054.

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We have studied phase transitions of higher dimensional charge black hole with spherical symmetry. We calculated the local energy and local temperature and find that these state parameters satisfy the first law of thermodynamics. We analyze the critical behavior of black hole thermodynamic system by taking state parameters(Q,Φ)of black hole thermodynamic system, in accordance with considering the state parameters(P,V)of van der Waals system, respectively. We obtain the critical point of black hole thermodynamic system and find that the critical point is independent of the dual independent variables we selected. This result for asymptotically flat space is consistent with that for AdS spacetime and is intrinsic property of black hole thermodynamic system.

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Vřesťál, J., J. Pavlů, U. D. Wdowik, and M. Sob. "Modelling of phase equilibria in the Hf-V system below room temperature." Journal of Mining and Metallurgy, Section B: Metallurgy 53, no. 3 (2017): 239–47. http://dx.doi.org/10.2298/jmmb170704032v.

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Phase transformation from orthorhombic HfV2 structure to cubic C15 Laves phase structure, which occurs during heating at about 114 K, is well known. In this contribution, a thermodynamic description of this phenomenon is provided supported by ab initio calculations. We utilize the third generation of thermodynamic database extending the Scientific Group Thermodata Europe (SGTE) unary data to zero Kelvin and demonstrate that it may be also applied to intermetallic phases. The data from a recent thermodynamic assessment of the Hf-V system (valid for temperatures above 298.15 K) were used and extended to zero Kelvin by the same method as it was used for unary data. Under the assumption of validity of harmonic approximation and electronic contribution to the heat capacity, the thermodynamics of C15 and orthorhombic phase were described. With the help of ab initio approach, we demonstrate that the HfV2 orthorhombic phase and C15 Laves phase are mechanically stable at 0 K and thanks to entropy stabilization they are in equilibrium with pure element phases in the temperature region of structural change.

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Sun, Wenhao, Stephen T. Dacek, Shyue Ping Ong, Geoffroy Hautier, Anubhav Jain, William D. Richards, Anthony C. Gamst, Kristin A. Persson, and Gerbrand Ceder. "The thermodynamic scale of inorganic crystalline metastability." Science Advances 2, no. 11 (November 2016): e1600225. http://dx.doi.org/10.1126/sciadv.1600225.

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The space of metastable materials offers promising new design opportunities for next-generation technological materials, such as complex oxides, semiconductors, pharmaceuticals, steels, and beyond. Although metastable phases are ubiquitous in both nature and technology, only a heuristic understanding of their underlying thermodynamics exists. We report a large-scale data-mining study of the Materials Project, a high-throughput database of density functional theory–calculated energetics of Inorganic Crystal Structure Database structures, to explicitly quantify the thermodynamic scale of metastability for 29,902 observed inorganic crystalline phases. We reveal the influence of chemistry and composition on the accessible thermodynamic range of crystalline metastability for polymorphic and phase-separating compounds, yielding new physical insights that can guide the design of novel metastable materials. We further assert that not all low-energy metastable compounds can necessarily be synthesized, and propose a principle of ‘remnant metastability’—that observable metastable crystalline phases are generally remnants of thermodynamic conditions where they were once the lowest free-energy phase.

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Sheykhi, Ahmad, Seyed Hossein Hendi, Fatemeh Naeimipour, Shahram Panahiyan, and Behzad Eslam Panah. "Thermodynamic geometry of charged dilaton black holes in AdS spaces." Canadian Journal of Physics 94, no. 10 (October 2016): 1045–53. http://dx.doi.org/10.1139/cjp-2016-0387.

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It was shown that with the combination of three Liouville-type dilaton potentials, one can derive dilaton black holes in the background of anti-de-Sitter (AdS) spaces. In this paper, we further extend the study on the dilaton AdS black holes by investigating their thermodynamic instability through a geometry approach. First, we review thermodynamic quantities of the solutions and check the validity of the first law of thermodynamics. Then, we investigate phase transitions and stability of the solutions. In particular, we disclose the effects of the dilaton field on the stability of the black holes. We also employ the geometrical approach toward thermodynamical behavior of the system and find that the divergencies in the Ricci scalar coincide with roots and divergencies in the heat capacity. We find that the behavior of the Ricci scalar around divergence points depends on the type of the phase transition.

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8

Wittkopf, H., and P. Bräuer. "Thermodynamic Formulations of Excess and Absolute Values of Adsorption on Solid Surfaces: A Comparison of One- and Two-Phase Approaches." Adsorption Science & Technology 3, no. 4 (December 1986): 271–91. http://dx.doi.org/10.1177/026361748600300408.

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The generally used methods of thermodynamic adsorption analysis are summarized in two basic concepts: the two-phase approach (which is an adequate picture of volume phase thermodynamics in adsorption) and the one-phase approach (which uses excess values for the thermodynamic description of adsorption). Differential and integral molar values of adsorption Δ a X̄ and Δ a X in the two-phase approach are not identical with the corresponding excess values Δ a X̄s and Δ a Xs in the one-phase approach. Especially at high temperatures and high pressures they may be entirely different. It is shown that the experimental methods most usually in adsorption thermodynamics (as adsorption volumetry and gravimetry) give excess data which are to be used in the one-phase approach but which can be transformed to the two-phase approach. Using statistical thermodynamic calculations the difference between these basic concepts is shown over a wide temperature range for the first virial coefficient, the internal energy and the heat capacity of adsorption.

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9

HILFER, R. "SCALING THEORY AND THE CLASSIFICATION OF PHASE TRANSITIONS." Modern Physics Letters B 06, no. 13 (June 10, 1992): 773–84. http://dx.doi.org/10.1142/s0217984992000855.

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The recent classification theory for phase transitions (R. Hilfer, Physica Scripta 44, 321 (1991)) and its relation with the foundations of statistical physics is reviewed. First it is outlined how Ehrenfests classification scheme can be generalized into a general thermodynamic classification theory for phase transitions. The classification theory implies scaling and multiscaling thereby eliminating the need to postulate the scaling hypothesis as a fourth law of thermodynamics. The new classification has also led to the discovery and distinction of nonequilibrium transitions within equilibrium statistical physics. Nonequilibrium phase transitions are distinguished from equilibrium transitions by orders less than unity and by the fact that equilibrium thermodynamics and statistical mechanics become inapplicable at the critical point. The latter fact requires a change in the Gibbs assumption underlying the canonical and grandcanonical ensembles in order to recover the thermodynamic description in the critical limit.

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10

Michaelsen, C., C. Gente, and R. Bormann. "Phase formation and thermodynamics of unstable Cu–Cr alloys." Journal of Materials Research 12, no. 6 (June 1997): 1463–67. http://dx.doi.org/10.1557/jmr.1997.0201.

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The quantitative description of highly nonequilibrium processes for the preparation of metastable and unstable phases requires the determination of the thermodynamic functions of the system under investigation. However, in systems such as Cu–Cr which are immiscible in the equilibrium states, the determination of the thermodynamic functions over the entire concentration range is often difficult if not impossible because reliable experimental data are not available for the metastable or unstable regime. The present paper demonstrates that such data can be obtained by a combination of thin film deposition techniques and differential scanning calorimetry. It is concluded that the phase formation in such thin films can be described in terms of the thermodynamics of the system, even when the heats of mixing are highly positive. The results indicate that models of the regular solution type still provide a reasonable description of the thermodynamic functions of such alloys.

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11

Vischi, Francesco, Matteo Carrega, Alessandro Braggio, Pauli Virtanen, and Francesco Giazotto. "Thermodynamics of a Phase-Driven Proximity Josephson Junction." Entropy 21, no. 10 (October 15, 2019): 1005. http://dx.doi.org/10.3390/e21101005.

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We study the thermodynamic properties of a superconductor/normal metal/superconductor Josephson junction in the short limit. Owing to the proximity effect, such a junction constitutes a thermodynamic system where phase difference, supercurrent, temperature and entropy are thermodynamical variables connected by equations of state. These allow conceiving quasi-static processes that we characterize in terms of heat and work exchanged. Finally, we combine such processes to construct a Josephson-based Otto and Stirling cycles. We study the related performance in both engine and refrigerator operating mode.

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12

Quevedo, Hernando, María N. Quevedo, and Alberto Sánchez. "Geometrothermodynamics of black hole binary systems." International Journal of Modern Physics D 29, no. 08 (May 20, 2020): 2050053. http://dx.doi.org/10.1142/s0218271820500534.

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We study a stationary and axisymmetric binary system composed of two identical Kerr black holes, whose physical parameters satisfy the Smarr thermodynamic formula. Then, we use the formalism of geometrothermodynamics to show that the spatial distance between the black holes must be considered as a thermodynamic variable. We investigate the main thermodynamic properties of the system by using the contact structure of the phase-space, which generates the first law of thermodynamics and the equilibrium conditions. The phase transition structure of the system is investigated through the curvature singularities of the equilibrium space. It is shown that the thermodynamic and stability properties and the phase transition structure of the binary system strongly depend on the distance between the black holes.

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13

Shalaby, Asmaa G. "GUP deformed phase-space and axiomatic thermodynamic self-consistency." International Journal of Modern Physics A 34, no. 06n07 (March 10, 2019): 1950039. http://dx.doi.org/10.1142/s0217751x19500398.

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Based on the generalized uncertainty principle (GUP) with a deformation of the phase-space, the partition function has recently been modified. In the present work, we analyze the self-consistency of the axiomatic thermodynamics derived from the deformed partition function. First, we set up the thermodynamic quantities such as pressure, energy density, entropy and number density, then we extend the study for testing the approval of consistency. We found that the deformed phase-space satisfies the axiomatic self-consistency of thermodynamics. We would expect the effects of GUP to be more pronounced at high frequencies, but the used deformed phase-space factor would still diverge as [Formula: see text] approaches [Formula: see text].

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14

Cai, Yuan Zhen. "Irreversible Thermodynamic Description of Domain Occurrences in Ferroics." Advanced Materials Research 560-561 (August 2012): 140–44. http://dx.doi.org/10.4028/www.scientific.net/amr.560-561.140.

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Based on the irreversible thermodynamics, a irreversible thermodynamic description of domain occurrences in ferroics such as ferroelectrics, ferromagnetics and ferroelastics was given. The ferroic domain structures occur at the ferroic phase transitions from the prototype phases to the ferroic phases. The processes of transition are stationary state processes so that the principle of minimum entropy production is satisfied. The domain occurrences are a consequence of this principle. The time-spatial symmetry related to the domains and their occurrences was also expounded.

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15

Ramos-Hernandez, J. J., J. Porcayo-Calderon, V. M. Salinas-Bravo, C. D. Arrieta-Gonzalez, J. G. Gonzalez-Rodriguez, and L. Martinez-Gomez. "Phase Stability Diagrams for High Temperature Corrosion Processes." Mathematical Problems in Engineering 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/542061.

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Corrosion phenomena of metals by fused salts depend on chemical composition of the melt and environmental conditions of the system. Detail knowledge of chemistry and thermodynamic of aggressive species formed during the corrosion process is essential for a better understanding of materials degradation exposed to high temperature. When there is a lack of kinetic data for the corrosion processes, an alternative to understand the thermodynamic behavior of chemical species is to utilize phase stability diagrams. Nowadays, there are several specialized software programs to calculate phase stability diagrams. These programs are based on thermodynamics of chemical reactions. Using a thermodynamic data base allows the calculation of different types of phase diagrams. However, sometimes it is difficult to have access to such data bases. In this work, an alternative way to calculate phase stability diagrams is presented. The work is exemplified in the Na-V-S-O and Al-Na-V-S-O systems. This system was chosen because vanadium salts is one of the more aggressive system for all engineering alloys, especially in those processes where fossil fuels are used.

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Kaufman, Miron, and Petru S. Fodor. "Analogy between Thermodynamic Phase Transitions and Creeping Flows in Rectangular Cavities." Symmetry 12, no. 11 (November 12, 2020): 1859. http://dx.doi.org/10.3390/sym12111859.

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An analogy is found between the streamline function corresponding to Stokes flows in rectangular cavities and the thermodynamics of phase transitions and critical points. In a rectangular cavity flow, with no-slip boundary conditions at the walls, the corners are fixed points. The corners defined by a stationary and a moving wall, are found to be analogous to a thermodynamic first-order transition point. In contrast, the corners defined by two stationary walls correspond to thermodynamic critical points. Here, flow structures, also known as Moffatt eddies, form and act as stagnation regions where mixing is impeded. A third stationary point occurs in the middle region of the channel and it is analogous to a high temperature thermodynamic fixed point. The numerical results of the fluid flow modeling are correlated with analytical work in the proximity of the fixed points.

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Melnick, A. B., V. K. Soolshenko, and K. H. Levchuk. "Thermodynamic Prediction of Phase Composition of Transition Metals High-Entropy Alloys." METALLOFIZIKA I NOVEISHIE TEKHNOLOGII 42, no. 10 (December 8, 2020): 1387–400. http://dx.doi.org/10.15407/mfint.42.10.1387.

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Lisachuk, G. V. "Thermodynamic analysis of solid phase reactions in SrO-Al2O3-SiO2 system." Functional materials 23, no. 1 (March 15, 2016): 71–74. http://dx.doi.org/10.15407/fm23.01.071.

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19

Végh, Ádám, Csaba Mekler, and György Kaptay. "A Unified Theoretical Framework to Model Bulk, Surface and Interfacial Thermodynamic Properties of Immiscible Liquid Alloys." Materials Science Forum 752 (March 2013): 10–19. http://dx.doi.org/10.4028/www.scientific.net/msf.752.10.

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Bulk, surface and interface thermodynamics of immiscible liquid alloys are considered within a unified theoretical framework. For bulk thermodynamic functions the exponential and the combined linear-exponential equations are discussed, obeying the 4th law of thermodynamics. Surface phase transition is discussed in details. For surface and interface thermodynamics the monolayer Butler equation is compared to the multilayer model. During further assessment of bulk thermodynamic data of immiscible liquid alloys their experimentally measured surface tension and interfacial energy should be also taken into account, coupled with the models presented here.

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BANDYOPADHYAY, TANWI, and SUBENOY CHAKRABORTY. "THE LAWS OF THERMODYNAMICS AND THERMODYNAMIC STABILITY OF THE MODIFIED CHAPLYGIN GAS." Modern Physics Letters A 25, no. 32 (October 20, 2010): 2779–93. http://dx.doi.org/10.1142/s0217732310034171.

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Laws of thermodynamics have been examined for the universe filled with a perfect fluid, obeying an adiabatic equation of state p = γρ-A/ρα (called modified Chaplygin gas), where γ, A and α are positive constants and ρ and p are energy density and thermodynamic pressure respectively. Using general thermodynamics, the behavior of temperature and the thermodynamic stability has been discussed for modified Chaplygin gas. A scenario is obtained such that the thermal equation of state depends on both temperature and volume and there will be thermodynamic stability during the expansion process so that the fluid cools down through the expansion without any phase transition (or passing through any critical point).

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Saunders, N., and A. P. Miodownik. "Thermodynamic aspects of amorphous phase formation." Journal of Materials Research 1, no. 1 (February 1986): 38–46. http://dx.doi.org/10.1557/jmr.1986.0038.

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The glass-forming ability of the three alloy systems Co–Zr, Cu–Zr, and Ni–Zr has been analyzed for three distinct production routes: (1) liquid quenching, (2) vapor deposition, and (3) solidstate reaction. Using the free energy and heats of formation curves obtained from the thermodynamic characterization of the respective alloy systems, a satisfactory rationale can be obtained for amorphous phase formation by all three routes. The analysis shows that while amorphous phase formation by quenching from the high-temperature liquid is clearly dependent on factors such as quench rate and the value TG/TM, it is the low-temperature stability of the amorphous phase relative to the other crystalline structures that enables amorphous phases to be formed by both vapor deposition and solid-state reaction. The underlying free energy curves indicate the interesting possibility of a supersaturation sequence in the nucleation of an amorphous phase by solid-state reaction. The principles underlying thermodynamic characterizations are briefly discussed, and a characterization for Co–Zr is presented.

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Zhang, Li-Chun, and Ren Zhao. "The universal Ehrenfest scheme on black holes." Modern Physics Letters A 30, no. 36 (November 3, 2015): 1550187. http://dx.doi.org/10.1142/s0217732315501874.

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By use of the Jacobi determinant, we verify that, for a thermodynamic system which satisfies the first law of thermodynamics, if only there is second-order phase transition in the system, the Prigogine–Defay ratio is the constant 1. This conclusion is universal and independent of the concrete forms of the thermodynamic functions and also apply to black holes.

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XU, W. W., X. Y. SONG, and Z. X. ZHANG. "MULTIPHASE EQUILIBRIUM, PHASE STABILITY AND PHASE TRANSFORMATION IN NANOCRYSTALLINE ALLOY SYSTEMS." Nano 07, no. 02 (April 2012): 1250012. http://dx.doi.org/10.1142/s1793292012500129.

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A nanoscale thermodynamic approach is developed to quantify the multiphase equilibrium in nanocrystalline alloy systems. The nanoscale multiphase equilibrium calculations indicate that the activities and mole numbers of phases in alloy systems change diversely as a function of the nanograin size at constant temperature, which results in distinctly different characteristics of phase stability and phase transformation behavior in nanocrystalline alloys with respect to coarse-grained polycrystalline counterparts. Take the nanocrystalline Sm–Co alloy system as an example, the diverse phase stabilities and phase transformations are demonstrated. To verify the thermodynamic predictions, a series of experiments on preparation and characterization of nanocrystalline SmCo3, Sm2Co7 and SmCo2 alloys have been performed. The experimental results are in agreement with the model calculations, which validate the present thermodynamic approach for nanoscale multiphase equilibrium.

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Saito, Kazuya. "Microphase-separated multicontinuous phase in low-molecular-mass thermotropic liquid crystals." Pure and Applied Chemistry 81, no. 10 (September 17, 2009): 1783–98. http://dx.doi.org/10.1351/pac-con-08-09-10.

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Extensive application of chemical thermodynamics to exotic aggregation formed in thermotropic liquid crystals is briefly described. Through thermodynamic analyses and considerations of experimental results on liquid crystals, the unexpected sharing of common properties by thermo- and lyotropic liquid crystals is demonstrated. In some thermotropic liquid crystals, the terminal alkyl chain attached to the molecular core is highly disordered, as indicated by the magnitude of configurational entropy. The molten chain serves as intramolecular solvent (self-solvent), as evidenced by the close similarity between phase diagrams against chain length and composition in the binary system with n-alkane. These facts lead to the quasi-binary picture of thermotropic liquid crystals. Consideration of the thermodynamic potential expanded in terms of density fluctuation gives a new insight into the multicontinuous phases formed in simple systems consisting of anisotropic, rodlike particles.

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Larrañaga, Alexis, Natalia Herrera, and Juliana Garcia. "Geometric Description of the Thermodynamics of the Noncommutative Schwarzschild Black Hole." Advances in High Energy Physics 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/641273.

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The thermodynamics of the noncommutative Schwarzschild black hole is reformulated within the context of the recently developed formalism of geometrothermodynamics (GTD). Using a thermodynamic metric which is invariant with respect to Legendre transformations, we determine the geometry of the space of equilibrium states and show that phase transitions, which correspond to divergencies of the heat capacity, are represented geometrically as singularities of the curvature scalar. This further indicates that the curvature of the thermodynamic metric is a measure of thermodynamic interaction.

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Övgün, Ali. "P-v Criticality of a Specific Black Hole in f(R) Gravity Coupled with Yang-Mills Field." Advances in High Energy Physics 2018 (June 25, 2018): 1–7. http://dx.doi.org/10.1155/2018/8153721.

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We study the P-v criticality of a specific charged AdS type black hole (SBH) in f(R) gravity coupled with Yang-Mills field. In the extended phase space, we treat the cosmological constant as a thermodynamic pressure. After we study the various thermodynamical quantities, we show that the thermodynamic properties of the SBH behave as a Van der Waals liquid-gas system at the critical points and there is a first-order phase transition between small-large SBH.

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Woodcock, Leslie V. "Thermodynamics of Gas–Liquid Colloidal Equilibrium States: Hetero-Phase Fluctuations." Entropy 21, no. 12 (December 3, 2019): 1189. http://dx.doi.org/10.3390/e21121189.

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Following on from two previous JETC (Joint European Thermodynamics Conference) presentations, we present a preliminary report of further advances towards the thermodynamic description of critical behavior and a supercritical gas-liquid coexistence with a supercritical fluid mesophase defined by percolation loci. The experimental data along supercritical constant temperature isotherms (T ≥ Tc) are consistent with the existence of a two-state mesophase, with constant change in pressure with density, rigidity, (dp/dρ) T, and linear thermodynamic state-functions of density. The supercritical mesophase is bounded by 3rd-order phase transitions at percolation thresholds. Here we present the evidence that these percolation transitions of both gaseous and liquid states along any isotherm are preceded by pre-percolation hetero-phase fluctuations that can explain the thermodynamic properties in the mesophase and its vicinity. Hetero-phase fluctuations give rise to one-component colloidal-dispersion states; a single Gibbs phase retaining 2 degrees of freedom in which both gas and liquid states with different densities percolate the phase volume. In order to describe the thermodynamic properties of two-state critical and supercritical coexistence, we introduce the concept of a hypothetical homo-phase of both gas and liquid, defined as extrapolated equilibrium states in the pre-percolation vicinity, with the hetero-phase fractions subtracted. We observe that there can be no difference in chemical potential between homo-phase liquid and gaseous states along the critical isotherm in mid-critical isochoric experiments when the meniscus disappears at T = Tc. For T > Tc, thermodynamic states comprise equal mole fractions of the homo-phase gas and liquid, both percolating the total phase volume, at the same temperature, pressure, and with a uniform chemical potential, stabilised by a positive finite interfacial surface tension.

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Li, Huai-Fan, Meng-Sen Ma, and Ya-Qin Ma. "Thermodynamic properties of black holes in de Sitter space." Modern Physics Letters A 32, no. 02 (December 29, 2016): 1750017. http://dx.doi.org/10.1142/s0217732317500171.

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We study the thermodynamic properties of Schwarzschild–de Sitter (SdS) black hole and Reissner–Nordström–de Sitter (RNdS) black hole in view of global and effective thermodynamic quantities. Making use of the effective first law of thermodynamics, we can derive the effective thermodynamic quantities of de Sitter black holes. It is found that these effective thermodynamic quantities also satisfy Smarr-like formula. Especially, the effective temperatures are nonzero in the Nariai limit. By calculating heat capacity and Gibbs free energy, we find SdS black hole is always thermodynamically stable and RNdS black hole may undergoes phase transition at some points.

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Sheykhi, A., and S. Hajkhalili. "Extended phase space and thermodynamic geometry of topological Born–Infeld-dilaton black holes." International Journal of Modern Physics D 25, no. 06 (May 2016): 1650062. http://dx.doi.org/10.1142/s0218271816500620.

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We consider an [Formula: see text]-dimensional topological black holes of Einstein-dilaton gravity in the presence of Born–Infeld nonlinear electrodynamics. We investigate the thermal stability in the grand canonical ensemble and show that depending on the values of the parameters, these types of black holes can experience an instable phase and with changing of the metric parameters, the stability can be influenced. Also, we study the phase transition of these black holes via thermodynamic geometry approach and show that two types of phase transition can be occurred. Finally, we extend thermodynamical space by considering dilaton field as an extensive thermodynamic parameter and check the phase transition points.

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Ahmed, Jamil. "An Overview of Black Hole Chemistry." Physical Sciences Forum 2, no. 1 (February 22, 2021): 11. http://dx.doi.org/10.3390/ecu2021-09308.

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The understanding the thermodynamic behavior of black holes using the concepts of chemistry will be discussed here. To establish the complete correspondence between the thermodynamics of an ordinary system and the thermodynamics of black holes, recent proposals suggest the identification of the mass of a black hole as the chemical enthalpy of an ordinary thermodynamic system. Similarly, the negative cosmological constant, surface gravity, and horizon area of a black hole is identified as the pressure, temperature, and entropy of a thermodynamic system. Consequently, black holes behave analogously to a variety of everyday phenomena. This allows an understanding of black holes using concepts of chemistry such as Van der Waals fluids, phase transitions, etc.

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Jiang, Q., and Z. P. Chen. "Thermodynamic phase stabilities of nanocarbon." Carbon 44, no. 1 (January 2006): 79–83. http://dx.doi.org/10.1016/j.carbon.2005.07.014.

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Wang, Y., B. Hu, S. Liu, and Y. Du. "Thermodynamic reassessment of the La-Mn system." Journal of Mining and Metallurgy, Section B: Metallurgy 48, no. 3 (2012): 391–94. http://dx.doi.org/10.2298/jmmb120717049w.

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The binary La-Mn system is investigated by CALPHAD approach. The experimental phase diagram and thermodynamic data available in the literature are critically reviewed and assessed using the thermodynamic models for the Gibbs energies of individual phases. A set of consistent thermodynamic data for the La-Mn system is obtained by optimization of the selected experimental data. The miscibility gap is no more existent in the optimized phase diagram. The calculated phase diagram agrees well with the experimental data.

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Tang, Ying, and Lijun Zhang. "On Gibbs Energy for the Metastable bcc_A2 Phase with a Thermal Vacancy in Metals and Alloys." Materials 12, no. 2 (January 17, 2019): 292. http://dx.doi.org/10.3390/ma12020292.

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An approach was proposed to obtain a reasonable thermodynamic description of a thermal vacancy in the metastable disordered body centered cubic (bcc_A2) phase, which had been consistently ignored in previous thermodynamic assessments. The present approach was first applied to obtain the thermodynamic descriptions for pure metastable bcc Ni and Zn, and then in the binary Ni-Zn system. The thermodynamic descriptions for both the metastable disordered bcc_A2 phase and the stable ordered bcc_B2  phases in the Ni-Zn binary system were updated based on the corresponding experimental equilibria. With these updated thermodynamic descriptions, several drawbacks, including the multiple solutions for thermal vacancy concentrations and the artificial phase boundaries in previous assessments, can be avoided. Moreover, the calculated phase boundaries and invariant reactions related to the  phase agree well with the experimental data.

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Zhao, Ren, Mengsen Ma, Huaifan Li, and Lichun Zhang. "On Thermodynamics of Charged and Rotating Asymptotically AdS Black Strings." Advances in High Energy Physics 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/371084.

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In this paper, we study thermodynamics of cylindrically symmetric black holes and calculate the equation of states and heat capacity of charged and rotating black strings. In the process, we treat the cosmological constant as a thermodynamic pressure and its conjugate quantity as a thermodynamic volume. It is shown that, when taking the equivalence between the thermodynamic quantities of black strings and the ones of general thermodynamic system, the isothermal compressibility and heat capacity of black strings satisfy the stability conditions of thermodynamic equilibrium and no divergence points exist for heat capacity. Thus, we obtain the conclusion that the thermodynamic system relevant to black strings is stable and there is no second-order phase transition for AdS black holes in the cylindrically symmetric spacetime.

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Gierlotka, Wojciech, and Sinn-wen Chen. "Thermodynamic descriptions of the Cu–Zn system." Journal of Materials Research 23, no. 1 (January 2008): 258–63. http://dx.doi.org/10.1557/jmr.2008.0035.

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Cu–Zn is an important binary alloy system. In the interested temperature range from 300 to 1500 K, there are eight phases, liquid, Cu, β, β′, γ, δ, ϵ, and Zn phases. The thermodynamic descriptions of the Cu–Zn system are reassessed using the CALPHAD method. A new description of liquid phase and simplified description of body-centered cubic (bcc) phase are proposed. Good agreement has been found among the calculated thermodynamic properties, phase diagram, and the experimental information.

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Sambasivan, S., and W. T. Petuskey. "Phase chemistry in the Ti-Si-N system: Thermochemical review with phase stability diagrams." Journal of Materials Research 9, no. 9 (September 1994): 2362–69. http://dx.doi.org/10.1557/jmr.1994.2362.

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The phase chemistry and thermodynamics of the Ti-Si-N system are reviewed leading to a revision of the ternary phase diagram at 1273 K to include the extended compositional ranges of δ-TiNx and Ti5Si3(Ny) and the compounds Ti3Si, Ti5Si4, and α-Ti. This same information is presented in the form of phase stability diagrams which plot the stability criteria for each phase as a function of thermodynamic activity of one component and the relative composition of the other two components. Plots in terms of log asi vs Ti/(Ti + N), log aN2 vs Si/(Ti + Si), and log aTi vs N/(Si + N) were constructed. All diagrams are consistent with current knowledge of phase compatibility and, therefore, are topologically correct. Further refinement will be possible as more accurate information on thermodynamics and compositional limits of solid solutions becomes available.

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Sangster, James Malcolm. "Calculation of phase diagrams and thermodynamic properties of 18 binary common-ion systems of Na,K,Ba//F,MoO4,WO4." Canadian Journal of Chemistry 74, no. 3 (March 1, 1996): 402–18. http://dx.doi.org/10.1139/v96-045.

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Phase diagram and thermodynamic data of 18 binary common-ion molten salt systems in Na,K,Ba//F,MoO4,WO4 were optimized by computer algorithm. The phase diagram data as well as single-salt data were retrieved from an extensive critical literature search. Expressions for the excess properties of solution phases and thermodynamic properties of intermediate compounds were thereby obtained. These data were used to generate a "best" phase diagram for each binary system considered. Key words: molten salts, phase diagrams, thermodynamic properties.

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Lavagno, A., D. Pigato, and G. Gervino. "Thermodynamic instabilities in high energy heavy-ion collisions." Modern Physics Letters B 29, no. 18 (July 10, 2015): 1550092. http://dx.doi.org/10.1142/s021798491550092x.

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One of the very interesting aspects of high energy heavy-ion collisions experiments is a detailed study of the thermodynamical properties of strongly interacting nuclear matter away from the nuclear ground state. In this direction, many efforts were focused on searching for possible phase transitions in such collisions. We investigate thermodynamic instabilities in a hot and dense nuclear medium where a phase transition from nucleonic matter to resonance-dominated [Formula: see text]-matter can take place. Such a phase transition can be characterized by both mechanical instability (fluctuations on the baryon density) and by chemical-diffusive instability (fluctuations on the strangeness concentration) in asymmetric nuclear matter. In analogy with the liquid–gas nuclear phase transition, hadronic phases with different values of antibaryon–baryon ratios and strangeness content may coexist. Such a physical regime could be, in principle, investigated in the future high-energy compressed nuclear matter experiments which will make it possible to create compressed baryonic matter with a high net baryon density.

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Abdellah, Z. Nait, Redoune Chegroune, Mourad Keddam, B. Bouarour, L. Haddour, and A. Elias. "The Phase Stability in the Fe-B Binary System: Comparison between the Interstitial and Substitutional Models." Defect and Diffusion Forum 322 (March 2012): 1–9. http://dx.doi.org/10.4028/www.scientific.net/ddf.322.1.

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In the present work, a thermodynamic study was carried out in order to analyze the thermodynamic stability of the and phases in equilibrium with the phase using the calculation of phase diagrams (Calphad) formalism. The two phases and are modelled as substitutional and interstitial solid solutions of boron. The expressions of the chemical potentials ofBandFeare derived in both phases to perform the thermodynamic calculations. A comparison is made between the results provided by the substitutional and interstitial models and good agreement is observed between these two models.

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Pradhan, Parthapratim. "Thermodynamic products in extended phase-space." International Journal of Modern Physics D 26, no. 02 (February 2017): 1750010. http://dx.doi.org/10.1142/s0218271817500109.

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We have examined the thermodynamic properties for a variety of spherically symmetric charged-AdS black hole (BH) solutions, including the charged AdS BH surrounded by quintessence dark energy and charged AdS BH in [Formula: see text] gravity in extended phase-space. This framework involves treating the cosmological constant as thermodynamic variable (for example: thermodynamic pressure and thermodynamic volume). Then they should behave as an analog of Van-der-Waal (VdW) like systems. In the extended phase-space we have calculated the entropy product and thermodynamic volume product of all horizons. The mass (or enthalpy) independent nature of the said product signals they are universal quantities. The divergence of the specific heat indicates that the second-order phase transition occurs under certain condition. In Appendix A, we have studied the thermodynamic volume products for axisymmetric spacetime and it is shown to be not universal in nature. Finally, in Appendix B, we have studied the [Formula: see text] criticality of Cauchy horizon for charged-AdS BH and found to be an universal relation of critical values between two horizons as [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]. The symbols are defined in the main work.

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41

Li, Yu Heng, Fei Xu, Peng Wu Yang, Jia Lian Li, Lu Jiang Zhou, Shu Liang Wang, Yuan Hua Lin, and Xing Jun Liu. "Thermodynamic Database of the Phase Diagrams in the Au-RE Binary Systems." Materials Science Forum 850 (March 2016): 433–38. http://dx.doi.org/10.4028/www.scientific.net/msf.850.433.

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The thermodynamic database has been developed for Au-RE binary systems. Based on the experimental data including thermodynamic properties and phase equilibrium, the thermodynamic assessments of phase diagrams in the Au-RE (RE: Nd, Dy, Yb, Gd, Tb, Sm, Lu) binary systems were carried out by using the CALPHAD (Calculation of Phase Diagrams) method. The Gibbs free energies of the solution phases were described by substitutional solution model, and all of the intermetallic compounds were described by sublattice models. The calculated phase diagrams are congruent with the available experimental data. Combined with the assessed Au-RE (RE: La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) binary systems, the thermodynamic database of Au-RE binary systems has been developed, and some significant information of thermodynamic properties and phase equilibrium could be calculated, which is important for the further development of Sn-Au-RE high-temperature lead-free solders.

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Zhao, Ming, and Qing Jiang. "Size Effect on Thermal Properties in Low-Dimensional Materials." Key Engineering Materials 444 (July 2010): 189–218. http://dx.doi.org/10.4028/www.scientific.net/kem.444.189.

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An extension of the classical thermodynamics to nanometer scale has been conducted to elucidate information regarding size dependence of phase transition functions and binary phase diagrams. The theoretical basis of the extension is Lindemanns criterion for solid melting, Motts expression for vibrational melting entropy, and Shis model for size dependent melting temperature. These models are combined into a unified one without adjustable parameters for melting temperatures of nanocrystals. It is shown that the melting temperature of nanocrystals may drop or rise depending on interface conditions and dimensions. The model has been extended and applied to size dependences of melting enthalpy, melting entropy, atomic cohesive energy. Moreover, the above modeling has been utilized to determine the size-dependent continuous binary solution phase diagrams. These thermodynamic approachs have extended the capability of the classical thermodynamics to the thermodynamic phenomena in the nanometer regime.

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Vojta, G. "Phase Equilibria, Phase Diagrams and Phase Transformations. Their Thermodynamic Basis." Zeitschrift für Physikalische Chemie 211, Part_2 (January 1999): 227–28. http://dx.doi.org/10.1524/zpch.1999.211.part_2.227.

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HILFER, R. "CLASSIFICATION THEORY FOR PHASE TRANSITIONS." International Journal of Modern Physics B 07, no. 26 (November 30, 1993): 4371–87. http://dx.doi.org/10.1142/s0217979293003711.

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A refined classification theory for phase transitions in thermodynamics and statistical mechanics in terms of their orders is introduced and analyzed. The refined thermodynamic classification is based on two independent generalizations of Ehrenfests traditional classification scheme. The statistical mechanical classification theory is based on generalized limit theorems for sums of random variables from probability theory and the newly defined block ensemble limit. The block ensemble limit combines thermodynamic and scaling limits and is similar to the finite size scaling limit. The statistical classification scheme allows for the first time a derivation of finite size scaling without renormalization group methods. The classification distinguishes two fundamentally different types of phase transitions. Phase transitions of order λ>1 correspond to well known equilibrium phase transitions, while phase transitions with order λ<1 represent a new class of transitions termed anequilibrium transitions. The generalized order λ varies inversely with the strength of fluctuations. First order and second order transitions play a special role in both classification schemes. First order transitions represent a limiting case separating equilibrium and anequilibrium transitions. The special role or second order transitions is shown to be related to the breakdown of hyperscaling. For anequilibrium transitions the nature of the heat bath in the canonical ensemble becomes important.

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Delogu, Francesco. "Thermodynamic Phase Transitions in Nanometer-Sized Metallic Systems." Materials Science Forum 653 (June 2010): 31–53. http://dx.doi.org/10.4028/www.scientific.net/msf.653.31.

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The present chapter deals with the characterization and description of phase transitions in metallic systems with characteristic size down to the nanometer range. In particular, the chapter focuses on the solid-to-liquid transition in nanometer-sized particles. After a short introduction to classical thermodynamics and to the way it copes with the general properties exhibited by nanometer-sized systems, a rapid overview of the state of the art in the field of the solid-to-liquid transition is given. The heterogeneous melting processes taking place in mesoscopic systems are discussed in terms of both classical thermodynamic and numerical simulation approaches. In the former case, attention is focused on the case of mesoscopic Sn particles, for which a relatively large amount of consistent experimental data exists as a consequence of previous calorimetric studies. In the latter case, the behavior of mesoscopic Cu particles is discussed.

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KIM, SEYONG. "PHASE DIAGRAM OF THE STRONG INTERACTION SYSTEM FROM LATTICE QCD." International Journal of Modern Physics: Conference Series 01 (January 2011): 28–33. http://dx.doi.org/10.1142/s2010194511000079.

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We briefly review recent progresses in studying QCD thermodynamics from lattice QCD. Investigation of QCD in zero baryon density shows a rapid cross-over with realistic (u, d, s) quark masses. Various improvements of lattice QCD action leads to more accurate determination of QCD thermodynamic properties. Although simulating QCD in non-zero baryon density is difficult due to "sign problem", steady progress is also achieved.

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Du, Y., J. R. Zhao, C. Zhang, H. L. Chen, and L. J. Zhang. "Thermodynamic modeling of the Fe-Mg-Si system." Journal of Mining and Metallurgy, Section B: Metallurgy 43, no. 1 (2007): 39–56. http://dx.doi.org/10.2298/jmmb0701039d.

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A thermo dynamic modeling for the Fe-Mg-Si system is conducted. All of the experimental phase diagram and thermodynamic data available from the literature are critically reviewed and assessed using thermo dynamic models for the Gibbs energies of individual phases. The thermodynamic parameters for ternary liquid as well as binary phases ?FeSi, (high-temperature form of FeSi2) and FeSi showing noticeable solubilities for Mg are evaluated in the optimization. Comparisons between the calculated and measured phase diagrams show that the measured isothermal six-lions at 1600?, 1454?, 727? and 710?C, the observed regions of primary phases are satisfactorily accounted for by the thermodynamic description. The limited thermodynamic data concerning the activity of Mg in liquid at 1350?C are found to be inconsistent with the well established phase relations. The liquidus projection and reaction scheme for the entire Fe-Mg-Si system are also presented. .

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Belosludov, V. R., O. S. Subbotin, D. S. Krupskii, T. Ikeshoji, R. V. Belosludov, Y. Kawazoe, and J. Kudoh. "Thermodynamic properties of hydrate phases immersed in ice phase." Journal of Physics: Conference Series 29 (January 1, 2006): 198–205. http://dx.doi.org/10.1088/1742-6596/29/1/039.

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Ansara, I. "Thermodynamic modelling of solution phases and phase diagram calculations." Pure and Applied Chemistry 62, no. 1 (January 1, 1990): 71–78. http://dx.doi.org/10.1351/pac199062010071.

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Drouelle, I., Sylvie Chatain, Christine Guéneau, Philippe Zeller, Didier Hamon, and Caroline Toffolon-Masclet. "Thermodynamic Study of Al-Li-O-Zr: Experimental Results and Thermodynamic Assessment." Advances in Science and Technology 45 (October 2006): 1925–30. http://dx.doi.org/10.4028/www.scientific.net/ast.45.1925.

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To better understand the formation of solid, liquid and gas phases between the Al-Li-O ceramics and zirconium (Zr) at temperatures above 1273 K, we built a thermodynamic database on the Al-Li-O-Zr quaternary system using the CALPHAD method. An accurate knowledge of both phase diagram and thermodynamic data of all the binary and ternary sub-systems is necessary to understand the phase relations in the quaternary. The thermodynamic descriptions of both Al-Li-Zr and Al-O-Zr ternary systems are presented. In addition, the Li-Al-O-Zr system was experimentally investigated using diffusion couples made of [ Zr / AlxLiyOz ] and [ ZrO2 / AlxLiyOz ] between 1373 K and 1573 K. The experimental results are compared with activity diagrams calculated with the thermodynamic database.

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Journal articles on the topic 'Thermodynamic phase'

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