scholarly journals Equations of State of Ca-Silicates and Phase Diagram of the CaSiO3 System under Upper Mantle Conditions

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 322
Author(s):  
Tatiana S. Sokolova ◽  
Peter I. Dorogokupets
Keyword(s):  
Phase Diagram ◽  
Heat Capacity ◽  
Thermal Expansion ◽  
Thermodynamic Model ◽  
Upper Mantle ◽  
Equations Of State ◽  
Calculated Density ◽  
Wide Range ◽  
Prem Model ◽  
Casio3 Perovskite

The equations of state of different phases in the CaSiO3 system (wollastonite, pseudowollastonite, breyite (walstromite), larnite (Ca2SiO4), titanite-structured CaSi2O5 and CaSiO3-perovskite) are constructed using a thermodynamic model based on the Helmholtz free energy. We used known experimental measurements of heat capacity, enthalpy, and thermal expansion at zero pressure and high temperatures, and volume measurements at different pressures and temperatures for calculation of parameters of equations of state of studied Ca-silicates. The used thermodynamic model has allowed us to calculate a full set of thermodynamic properties (entropy, heat capacity, bulk moduli, thermal expansion, Gibbs energy, etc.) of Ca-silicates in a wide range of pressures and temperatures. The phase diagram of the CaSiO3 system is constructed at pressures up to 20 GPa and temperatures up to 2000 K and clarifies the phase boundaries of Ca-silicates under upper mantle conditions. The calculated wollastonite–breyite equilibrium line corresponds to equation P(GPa) = −4.7 × T(K) + 3.14. The calculated density and adiabatic bulk modulus of CaSiO3-perovskite is compared with the PREM model. The calcium content in the perovskite composition will increase the density of mineral and it good agree with the density according to the PREM model at the lower mantle region.

Thermal Properties of CuGa2 Phase in Inert Atmosphere

2012 ◽  
Vol 326-328 ◽  
pp. 227-232 ◽  
Author(s):  
T.V. Kulikova ◽  
V.A. Bykov ◽  
K. Y. Shunyaev ◽  
A.B. Shubin
Keyword(s):  
Thermal Analysis ◽  
Phase Diagram ◽  
Thermal Decomposition ◽  
Heat Capacity ◽  
Thermal Expansion ◽  
Experimental Studies ◽  
Inert Atmosphere ◽  
Heat Conductivity Coefficient ◽  
Incongruent Melting ◽  
Modeling Methods

Thermal decomposition of copper digallide was studied using experimental (thermal analysis) and theoretical (thermodynamic modeling) methods. The temperatures of CuGa2incongruent melting are in satisfactory agreement between experimental and calculated values. Small differences with the phase diagram can be explained by minor non-stoichiometry of the alloy samples. The experimental studies of thermal diffusivity and thermal expansion of CuGa2were performed in the temperature range 298-500 K. The heat conductivity coefficient was further calculated using literary data concerning the density and heat capacity of the copper digallide.

scholarly journals AQUA: a collection of H2O equations of state for planetary models

2020 ◽  
Vol 643 ◽  
pp. A105 ◽  
Author(s):  
Jonas Haldemann ◽  
Yann Alibert ◽  
Christoph Mordasini ◽  
Willy Benz
Keyword(s):  
Equation Of State ◽  
Internal Energy ◽  
High Pressures ◽  
Equations Of State ◽  
Chemical Elements ◽  
Thermodynamic Quantities ◽  
Calculated Density ◽  
Temperature Range ◽  
Wide Range ◽  
The Impact

Context. Water is one of the key chemical elements in planetary structure modelling. Due to its complex phase diagram, equations of state often only cover parts of the pressure-temperature space needed in planetary modelling. Aims. We aim to construct an equation of state of H2O spanning a very wide range, from 0.1 Pa to 400 TPa and 150 to 105 K, which can be used to model the interior of planets. Methods. We combined equations of state valid in localised regions to form a continuous equation of state spanning over the above-mentioned pressure and temperature range. Results. We provide tabulated values for the most important thermodynamic quantities: the density, adiabatic temperature gradient, entropy, internal energy, and bulk speed of sound of water over this pressure and temperature range. For better usability we also calculated density-temperature and density-internal energy grids. We discuss further the impact of this equation of state on the mass radius relation of planets compared to other popular equations of state like ANEOS and QEOS. Conclusions. AQUA is a combination of existing equations of state useful for planetary models. We show that, in most regions, AQUA is a thermodynamic consistent description of water. At pressures above 10 GPa, AQUA predicts systematic larger densities than ANEOS or QEOS. This is a feature that was already present in a previously proposed equation of state, which is the main underlying equation of this work. We show that the choice of the equation of state can have a large impact on the mass-radius relation, which highlights the importance of future developments in the field of equations of state and regarding experimental data of water at high pressures.

Wide-range equations of state for organic liquids

2007 ◽  
Vol 5 ◽  
pp. 113-120 ◽  
Author(s):  
R.Kh. Bolotnova
Keyword(s):  
High Pressures ◽  
Equations Of State ◽  
Organic Liquids ◽  
Liquid Phases ◽  
Wide Range ◽  
High Pressures And Temperatures

The method of construction the wide-range equations of state for organic liquids, describing the gas and liquid phases including dissociation and ionization which occurs during an intense collapse of steam bubbles and accompanied by ultra-high pressures and temperatures, is proposed.

scholarly journals Universal behavior of the bosonic metallic ground state in a two-dimensional superconductor

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhuoyu Chen ◽  
Bai Yang Wang ◽  
Adrian G. Swartz ◽  
Hyeok Yoon ◽  
Yasuyuki Hikita ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Diagram ◽  
Quantum Phase Transitions ◽  
Metallic State ◽  
Two Dimensional ◽  
Metallic Behavior ◽  
Universal Behavior ◽  
Hall Resistivity ◽  
Wide Range ◽  
Metal State

AbstractAnomalous metallic behavior, marked by a saturating finite resistivity much lower than the Drude estimate, has been observed in a wide range of two-dimensional superconductors. Utilizing the electrostatically gated LaAlO3/SrTiO3 interface as a versatile platform for superconductor-metal quantum phase transitions, we probe variations in the gate, magnetic field, and temperature to construct a phase diagram crossing from superconductor, anomalous metal, vortex liquid, to the Drude metal state, combining longitudinal and Hall resistivity measurements. We find that the anomalous metal phases induced by gating and magnetic field, although differing in symmetry, are connected in the phase diagram and exhibit similar magnetic field response approaching zero temperature. Namely, within a finite regime of the anomalous metal state, the longitudinal resistivity linearly depends on the field while the Hall resistivity diminishes, indicating an emergent particle-hole symmetry. The universal behavior highlights the uniqueness of the quantum bosonic metallic state, distinct from bosonic insulators and vortex liquids.

Comparison of thermal expansion and heat capacity properties of various borosilicate glass-bonded strontium chloroapatite composites loaded with simulated pyrochemical waste

2014 ◽  
Vol 119 (3) ◽  
pp. 1825-1831 ◽  
Author(s):  
Binoy Kumar Maji ◽  
Hrudananda Jena ◽  
R. Venkata Krishnan ◽  
R. Asuvathraman ◽  
K. Ananthasivan ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Thermal Expansion ◽  
Borosilicate Glass

Heat capacity and thermal expansion of the itinerant helimagnet MnSi

2008 ◽  
Vol 20 (23) ◽  
pp. 235222 ◽  
Author(s):  
S M Stishov ◽  
A E Petrova ◽  
S Khasanov ◽  
G Kh Panova ◽  
A A Shikov ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Thermal Expansion

Heat Capacity and Thermal Expansion of M-Terbium Orthotantalate

2021 ◽  
Vol 499 (1) ◽  
pp. 70-72
Author(s):  
P. G. Gagarin ◽  
A. V. Guskov ◽  
V. N. Guskov ◽  
A. V. Khoroshilov ◽  
K. S. Gavrichev ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Thermal Expansion
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