scholarly journals Thermodynamic Optimization of the Ternary Ga-Sn-Te System Using Modified Quasichemical Model

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1363
Author(s):  
Bhupendra Kumar ◽  
Manas Paliwal ◽  
Chandra Sekhar Tiwary ◽  
Min-Kyu Paek
Keyword(s):  
Thermodynamic Properties ◽  
Solid Phase ◽  
Ternary Eutectic ◽  
Critical Evaluation ◽  
Regular Solution Model ◽  
Liquid Solution ◽  
Pair Approximation ◽  
Model Parameters ◽  
Thermodynamic Optimization ◽  
Quasichemical Model

Thermoelectric (TE) materials are of great interest to many researchers because they directly convert electric and thermal energy in a solid state. Various materials such as chalcogenides, clathrates, skutterudites, eutectic alloys, and intermetallic alloys have been explored for TE applications. The Ga-Sn-Te system exhibits promising potential as an alternative to the lead telluride (PbTe) based alloys, which are harmful to environments because of Pb toxicity. Therefore, in this study, thermodynamic optimization and critical evaluation of binary Ga-Sn, binary Sn-Te, and ternary Ga-Sn-Te systems have been carried out over the whole composition range from room temperature to above liquidus temperature using the CALPHAD method. It is observed that Sn-Te and Ga-Te liquids show the strong negative deviation from the ideal solution behavior. In contrast, the Ga-Sn liquid solution has a positive mixing enthalpy. These different thermodynamic properties of liquid solution were explicitly described using Modified Quasichemical Model (MQM) in the pair approximation. The asymmetry of ternary liquid solution in the Ga-Sn-Te system was considered by adopting the toop-like interpolation method based on the intrinsic property of each binary. The solid phase of SnTe was optimized using Compound Energy Formalism (CEF) to explain the high temperature homogeneity range, whereas solid solution, Body-Centered Tetragonal (BCT) was optimized using a regular solution model. Thermodynamic properties and phase diagram in the Ga-Sn-Te and its sub-systems were reproduced successfully by the optimized model parameters. Using the developed database, we also suggested several ternary eutectic compositions for designing TE alloy with improved properties.

scholarly journals Thermodynamic Modeling of Ni-C, Co-C, and Ni-Co-C Liquid Alloys Using the Modified Quasichemical Model

2020 ◽  
Author(s):  
Junmo Jeon ◽  
Sun-Yong Kwon ◽  
Daniel Lindberg ◽  
Min-Kyu Paek
Keyword(s):  
Short Range ◽  
Interpolation Method ◽  
Liquid Solution ◽  
Pair Approximation ◽  
Strong Interactions ◽  
Free Energies ◽  
Quasichemical Model ◽  
Liquid Phases ◽  
Short Range Ordering ◽  
Co Alloys

Abstract The strong interactions between the metallic elements and C in liquid Ni, Co, and Ni-Co alloys have been thermodynamically analyzed. The liquid solution properties in Ni-C and Co-C systems showed significant asymmetry because of the short-range ordering of C exhibited in the liquid solution. Using the modified quasichemical model in the pair approximation, the Ni-C and Co-C systems were re-optimized to simultaneously reproduce the present experimental results of the C solubility and the reported thermodynamic properties in the liquid phases. In particular, the partial enthalpy data of C in liquid Ni and Co alloys were considered for the first time on the thermodynamic assessment of Ni-C and Co-C liquid solutions. The asymmetric interpolation method was introduced to evaluate the Gibbs free energy in the ternary system based on the binary Gibbs free energies in the Ni-C and Co-C systems. The C solubility data measured in the ternary Ni-Co-C alloy melt over a wide Co concentration range were successfully reproduced without any additional ternary model parameter by considering the short-range ordering of C.

scholarly journals Thermodynamic Assessment of Liquid Fe-Ni-C Alloy Using Modified Quasichemical Model

JOM ◽  
2020 ◽  
Author(s):  
Min-Kyu Paek ◽  
Junmo Jeon ◽  
Manas Paliwal ◽  
Arijit Biswas ◽  
Daniel Lindberg ◽  
...  
Keyword(s):  
Thermodynamic Assessment ◽  
Enthalpy Of Mixing ◽  
Liquid Solution ◽  
Solubility Limit ◽  
Pair Approximation ◽  
Quasichemical Model ◽  
Entire Concentration Range ◽  
Short Range Ordering ◽  
Rich Side ◽  
Partial Enthalpy Of Mixing

AbstractThe liquid solution properties in the Fe-Ni and Fe-Ni-C systems have been thermodynamically assessed using the modified quasichemical model in the pair approximation. The asymmetry of the Fe-Ni and Fe-Ni-C alloy melts was verified by measuring the melting points of Fe-Ni binary alloys on the Ni-rich side, and the C solubility limit in Fe-Ni melt over the entire concentration range at 1500°C and 1600°C. The solubility minimum of C and the maximum partial enthalpy of mixing of C in the ternary Fe-Ni-C system occurred at near the maximum short-range ordering composition of the binary Fe-Ni liquid solution. The extrema of the partial properties of C in the ternary Fe-Ni-C system were successfully reproduced with only one constant adjustable ternary parameter.

Critical evaluation and the thermodynamic optimization of the Sn-O system

2021 ◽  
Author(s):  
Tiantian Yin ◽  
Jaesung Lee ◽  
Elmira Moosavi-Khoonsari ◽  
In-Ho Jung
Keyword(s):  
Critical Evaluation ◽  
Thermodynamic Optimization

scholarly journals Thermal conductivity of unsaturated clay-rocks

2010 ◽  
Vol 14 (1) ◽  
pp. 91-98 ◽  
Author(s):  
D. Jougnot ◽  
A. Revil
Keyword(s):  
Thermal Conductivity ◽  
Porous Material ◽  
Solid Phase ◽  
Model Parameters ◽  
Electrical Parameters ◽  
New Model ◽  
Unsaturated Clay ◽  
Unsaturated Porous Material ◽  
Clay Rocks ◽  
Good Agreement

Abstract. The parameters used to describe the electrical conductivity of a porous material can be used to describe also its thermal conductivity. A new relationship is developed to connect the thermal conductivity of an unsaturated porous material to the thermal conductivity of the different phases of the composite, and two electrical parameters called the first and second Archie's exponents. A good agreement is obtained between the new model and thermal conductivity measurements performed using packs of glass beads and core samples of the Callovo-Oxfordian clay-rocks at different saturations of the water phase. We showed that the three model parameters optimised to fit the new model against experimental data (namely the thermal conductivity of the solid phase and the two Archie's exponents) are consistent with independent estimates. We also observed that the anisotropy of the effective thermal conductivity of the Callovo-Oxfordian clay-rock was mainly due to the anisotropy of the thermal conductivity of the solid phase.

Calculation on the Free Energy of Mixing of some Silane Systems

2011 ◽  
Vol 391-392 ◽  
pp. 1017-1021
Author(s):  
Ru Zhang ◽  
Yan Fen Wu ◽  
Ping Hu
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Activity Coefficients ◽  
Influence Factors ◽  
Critical Parameters ◽  
Model Parameters ◽  
Free Energies ◽  
Wilson Model ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

Six binary silane systems were chosen to calculate the activity coefficients (γ) and free energies of mixing (ΔGm). These systems included: methyldichlorosilane + methyltrichlorosilane, methyldichlorosilane + methylvinyldichlorosilane, methyldichlorosilane + toluene, methyltrichlorosilane + methylvinyldichlorosilane, methyltrichlorosilane + toluene, methylvinyldichlorosilane + toluene. Based on the Antoine constants, critical parameters of the pure components and Wilson model parameters, γ and ΔGmwere calculated. The influence factors of these thermodynamic properties were also discussed.

scholarly journals Thermodynamic Study of Tl6SBr4 Compound and Some Regularities in Thermodynamic Properties of Thallium Chalcohalides

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Dunya Mahammad Babanly ◽  
Qorkhmaz Mansur Huseynov ◽  
Ziya Saxaveddin Aliev ◽  
Dilgam Babir Tagiyev ◽  
Mahammad Baba Babanly
Keyword(s):  
Phase Diagram ◽  
Thermodynamic Properties ◽  
Thermodynamic Functions ◽  
Chemical Bonding ◽  
Electromotive Force ◽  
Solid Phase ◽  
Thermodynamic Study ◽  
Degree Of Ionization ◽  
Emf Measurements ◽  
Concentration Cells

The solid-phase diagram of the Tl-TlBr-S system was clarified and the fundamental thermodynamic properties of Tl6SBr4 compound were studied on the basis of electromotive force (EMF) measurements of concentration cells relative to a thallium electrode. The EMF results were used to calculate the relative partial thermodynamic functions of thallium in alloys and the standard integral thermodynamic functions (-ΔfG0, -ΔfH0, and S0298) of Tl6SBr4 compound. All data regarding thermodynamic properties of thallium chalcogen-halides are generalized and comparatively analyzed. Consequently, certain regularities between thermodynamic functions of thallium chalcogen-halides and their binary constituents as well as degree of ionization (DI) of chemical bonding were revealed.

Solid-Phase Equilibria and Thermodynamic Properties of Phases in the Tm–Te System

2021 ◽  
Vol 95 (5) ◽  
pp. 926-932
Author(s):  
S. Z. Imamaliyeva ◽  
I. F. Mekhdiyeva ◽  
V. A. Gasymov ◽  
D. M. Babanly ◽  
D. B. Tagiev ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Phase Equilibria ◽  
Solid Phase

scholarly journals Generalization of the Unified Analytic Melt-Shear Model to Multi-Phase Materials: Molybdenum as an Example

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 86 ◽  
Author(s):  
Leonid Burakovsky ◽  
Darby Luscher ◽  
Dean Preston ◽  
Sky Sjue ◽  
Diane Vaughan
Keyword(s):  
Shear Modulus ◽  
Solid Phase ◽  
Model Parameters ◽  
Quantum Molecular Dynamics ◽  
Face Centered Cubic ◽  
Shear Model ◽  
Bcc Structure ◽  
Face Centered ◽  
Multi Phase ◽  
Theoretical Results

The unified analytic melt-shear model that we introduced a decade ago is generalized to multi-phase materials. A new scheme for calculating the values of the model parameters for both the cold ( T = 0 ) shear modulus ( G ) and the melting temperature at all densities ( ρ ) is developed. The generalized melt-shear model is applied to molybdenum, a multi-phase material with a body-centered cubic (bcc) structure at low ρ which loses its dynamical stability with increasing pressure (P) and is therefore replaced by another (dynamically stable) solid structure at high ρ . One of the candidates for the high- ρ structure of Mo is face-centered cubic (fcc). The model is compared to (i) our ab initio results on the cold shear modulus of both bcc-Mo and fcc-Mo as a function of ρ , and (ii) the available theoretical results on the melting of bcc-Mo and our own quantum molecular dynamics (QMD) simulations of one melting point of fcc-Mo. Our generalized model of G ( ρ , T ) is used to calculate the shear modulus of bcc-Mo along its principal Hugoniot. It predicts that G of bcc-Mo increases with P up to ∼240 GPa and then decreases at higher P. This behavior is intrinsic to bcc-Mo and does not require the introduction of another solid phase such as Phase II suggested by Errandonea et al. Generalized melt-shear models for Ta and W also predict an increase in G followed by a decrease along the principal Hugoniot, hence this behavior may be typical for transition metals with ambient bcc structure that dynamically destabilize at high P. Thus, we concur with the conclusion reached in several recent papers (Nguyen et al., Zhang et al., Wang et al.) that no solid-solid phase transition can be definitively inferred on the basis of sound velocity data from shock experiments on Mo. Finally, our QMD simulations support the validity of the phase diagram of Mo suggested by Zeng et al.

Sign in / Sign up

Export Citation Format

Share Document