scholarly journals Thermodynamic description of the Al-Cu-Yb ternary system supported by first-principles calculations

2016 ◽  
Vol 52 (2) ◽  
pp. 177-183 ◽  
Author(s):  
G. Huang ◽  
L. Liu ◽  
L. Zhang ◽  
Z. Jin
Keyword(s):  
Ternary System ◽  
First Principles ◽  
Thermodynamic Description ◽  
Theoretical Data ◽  
Intermetallic Phases ◽  
Calphad Method ◽  
First Principles Calculations ◽  
Self Consistent ◽  
Ternary Intermetallic Compounds ◽  
Phase Relationships

Phase relationships of the ternary Al-Cu-Yb system have been assessed using a combination of CALPHAD method and first principles calculations. A self-consistent thermodynamic parameter was established based on the experimental and theoretical information. Most of the binary intermetallic phases, except Al3Yb, Al2Yb, Cu2Yb and Cu5Yb, were assumed to be zero solubility in the ternary system. Based on the experimental data, eight ternary intermetallic compounds were taken into consideration in this system. Among them, three were treated as line compounds with large homogeneity ranges for Al and Cu. The others were treated as stoichiometric compounds. The calculated phase diagrams were in agreement with available experimental and theoretical data.

Thermodynamic description of Ge-Mn-Si

2014 ◽  
Vol 1642 ◽  
Author(s):  
Alexandre Berche ◽  
Jean-Claude Tédenac ◽  
Philippe Jund ◽  
Stéphane Gorsse
Keyword(s):  
Solid Solution ◽  
Gibbs Energy ◽  
First Principles ◽  
Thermodynamic Description ◽  
Intermetallic Phases ◽  
Calphad Method ◽  
Enthalpies Of Formation ◽  
Mixing Enthalpy ◽  
First Principles Calculations ◽  
First Time

ABSTRACTLiterature data of the Mn-Si system is analyzed and discordances are pointed out. First principles calculations are performed to clarify the enthalpies of formation of the intermetallic phases. Especially the enthalpies of formation of the various possible structures of the MnSix are discussed. On the basis of these new data, a thermodynamic description of the Gibbs energy of the phases is performed using the Calphad method. The system Ge-Mn is also assessed using the Calphad method for the first time.The mixing enthalpy in the D88 solid solution is calculated between Mn5Ge3 and Mn5Si3 by DFT calculations.Finally a thermodynamic description of the ternary system is suggested. Especially the solubility of germanium in MnSix is modeled.

scholarly journals First-principles and CALPHAD-type study of the Ir-Mo and Ir-W systems

2020 ◽  
Vol 56 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Y.-Y. Huang ◽  
B. Wu ◽  
F. Li ◽  
L.-L. Chen ◽  
Z.-X. Deng ◽  
...  
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Thermodynamic Property ◽  
Phase Equilibria ◽  
First Principles ◽  
Critical Evaluation ◽  
Intermetallic Phases ◽  
First Principles Calculations ◽  
Property Data ◽  
Self Consistent

This study presents the thermodynamic modeling of the Ir-Mo and Ir-W systems by means of the CALPHAD (CALculation of PHAse Diagrams) approach supported with the first-principles calculations. A critical evaluation of the phase equilibria and the thermodynamic property data in literature was conducted for both systems. Due to the lack of experimental data, the first-principles calculations were applied to obtain the enthalpies of the solid and intermetallic phases. The thermodynamic parameters were assessed using the PARROT module of Thermo-Calc. A set of self-consistent parameters for the Ir-Mo and Ir-W systems was obtained after the optimization. Satisfactory agreement between the calculated results and the experimental data, including phase equilibria and thermodynamic properties was achieved.

scholarly journals Thermodynamic modeling of the In-Sc and In-Y systems supported by first-principles calculations

2018 ◽  
Vol 54 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Z. Hu ◽  
C. Huang ◽  
J. Tu ◽  
Y. Huang ◽  
A. Dong
Keyword(s):  
Intermetallic Compounds ◽  
Thermodynamic Modeling ◽  
First Principles ◽  
Regular Solution Model ◽  
Calphad Method ◽  
Enthalpies Of Formation ◽  
Thermodynamic Optimization ◽  
First Principles Calculations ◽  
Self Consistent ◽  
Good Agreement

Based on an assessment of the phase equilibria and thermodynamic data in the literature, the thermodynamic modeling of the In?Sc and In?Y systems was carried out by means of the calculation of phase diagram (CALPHAD) method supported by first-principles calculations. The solution phases, i.e., liquid, (In), (?Sc), (?Sc), (?Y) and (?Y), were modeled with the substitutional regular solution model. Ten intermetallic compounds, including InSc3, InSc2, In4Sc5, InSc, In2Sc, In3Sc, InY2, InY, In5Y3, and In3Y were described as stoichiometric phases, while In3Y5 was modeled with a sublattice model with respect to its homogeneity range. The enthalpies of formation of the intermetallic compounds at 0 K were computed using firstprinciple calculations and were used as input for the thermodynamic optimization. A set of self-consistent thermodynamic parameters for both the In?Sc and In?Y systems were obtained and the calculated phase diagrams are in good agreement with the experimental data.

scholarly journals Thermodynamic reassessment of Au-Pt-Sn system

2021 ◽  
Author(s):  
Jie-Qiong Hu ◽  
Ming Xie ◽  
Yongtai Chen ◽  
Jiheng Fang ◽  
Qiao Zhang
Keyword(s):  
Experimental Data ◽  
Phase Diagram ◽  
Phase Composition ◽  
Ternary System ◽  
First Principles ◽  
Catalytic Properties ◽  
Calphad Method ◽  
First Principles Calculations ◽  
Formation Enthalpies ◽  
Equilibrium Structures

Abstract Au-Pt-Sn alloys are a novel class of materials with promising catalytic properties. This study provides updated information on phase equilibrium structures and thermodynamics of the Au-Pt-Sn ternary system. The formation enthalpies of Au-Sn and Pt-Sn binary subsystems were predicted by first principles calculations and these values were further refined by CALPHAD method. The results obtained accurately reproduced the experimental data. The reassessed phase diagram of the Au-Pt-Sn ternary system accurately described the phase composition of several Au-Pt-Sn alloys, which is essential for further modifications of these materials.

scholarly journals Thermodynamic assessment of the Pb-Sr system

2017 ◽  
Vol 53 (3) ◽  
pp. 179-187 ◽  
Author(s):  
H. Zhang ◽  
C. Zhang ◽  
W.W. Wang ◽  
Y. Du ◽  
P. Zhou ◽  
...  
Keyword(s):  
First Principles ◽  
Thermodynamic Assessment ◽  
Thermodynamic Description ◽  
Experimental Information ◽  
Enthalpies Of Formation ◽  
First Principles Calculations ◽  
Exponential Polynomials ◽  
Self Consistent ◽  
Five Phases ◽  
Measured Phase Diagram

The Pb-Sr system has been critically reviewed and modeled by means of the CALPHAD (CALculation of PHAse Diagrams) approach. It contains seven stoichiometric compounds, i.e. SrPb3, Sr3Pb5, Sr2Pb3, SrPb, Sr5Pb4, Sr5Pb3 and Sr2Pb, in which the SrPb3 and Sr2Pb phases melt congruently, and the other five phases form via peritectic reactions. The enthalpies of formation for the intermetallic compounds at 0 K are provided by first-principles calculations. The liquid, fcc and bcc phases are modeled as substitutional solution phases. Both Redlich-Kister and exponential polynomials are used to describe the excess Gibbs energy of the liquid. Two sets of self-consistent thermodynamic parameters are obtained by considering reliable experimental data and the computed enthalpies of formation. Comprehensive comparisons between the calculated and measured phase diagram and thermodynamic data show that the experimental information is satisfactorily accounted for by the present thermodynamic description.

First-Principles Total Energy Study of NbCr2 + V Laves Phase Ternary System

1998 ◽  
Vol 552 ◽  
Author(s):  
Alim Ormeci ◽  
S. P. Chen ◽  
John M. Wills ◽  
R. C. Albers
Keyword(s):  
Ternary System ◽  
Total Energy ◽  
Density Of States ◽  
First Principles ◽  
Laves Phase ◽  
Full Potential ◽  
Self Consistent ◽  
Substitutional Defects ◽  
Cohesive Energies ◽  
Formation Energies

ABSTRACTThe C15 NbCr2 + V Laves phase ternary system is studied by using a first-principles, self-consistent, full-potential total energy method. Equilibrium lattice parameters, cohesive energies, density of states and formation energies of substitutional defects are calculated. Results of all these calculations show that in the C15 NbCr2 + V compounds, V atoms substitute Cr atoms only.

Thermodynamic Calculation of Phase Equilibria in the Mn-RE (RE=Nd, Gd, Dy) Binary Systems

2017 ◽  
Vol 898 ◽  
pp. 1036-1041
Author(s):  
M.H. Rong ◽  
S.D. Lin ◽  
Jiang Wang ◽  
H.Y. Zhou ◽  
G.H. Rao
Keyword(s):  
Magnetic Properties ◽  
Thermodynamic Properties ◽  
Phase Equilibria ◽  
Thermodynamic Calculation ◽  
Binary Systems ◽  
Ternary Systems ◽  
Experimental Information ◽  
Calphad Method ◽  
Self Consistent ◽  
Ternary Intermetallic Compounds

Ternary intermetallic compounds with rare earth elements and transition metals in the RE-Mn-X (X=Si, Ge, Sn etc.) ternary systems show interesting magnetic properties. As key sub-binary systems of the RE-Mn-X (X=Si, Ge, Sn etc.) ternary systems, the information of phase equilibria and thermodynamic properties of the Mn-RE (RE=Nd, Gd, Dy) binary systems are indispensable to explore the RE-Mn-X (X=Si, Ge, Sn etc.) alloys with better magnetic properties. In this work, the experimental data of phase equilibria and thermodynamic properties of the Mn-RE (RE=Nd, Gd, Dy) binary systems in the published literature were reviewed. Based on the available experimental information, thermodynamic calculation of phase equilibria of the Mn-RE (RE=Nd, Gd, Dy) binary systems was performed using the CALPHAD method. As a result, further experimental investigation and thermodynamic optimization would be still necessary in order to develop the self-consistent and compatible thermodynamic database of the RE-Mn-based alloy systems.

First-principles Study of the Electronic Structure and Local Moment Interactions in PuAm Alloy

2008 ◽  
Vol 1104 ◽  
Author(s):  
Myung Joon Han ◽  
Xiangang Wan ◽  
Sergej Y Savrasov
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Local Density ◽  
Exchange Interactions ◽  
Kondo Lattice ◽  
First Principles Calculations ◽  
Correlation Effects ◽  
Self Consistent ◽  
5F Electrons ◽  
Zero Moment

AbstractExpected to provide a clue about the origin of zero moment in the bulk phase of Plutonium, Pu1-xAmx alloys have attracted a great attention, in which upon doping the system transforms from the Kondo lattice to the diluted impurity limit. To understand the electronic structure and the magnetic properties of Pu in different crystal environments, we performed fully self-consistent first-principles calculations of the PuAm system based on the local density approximation (LDA) combined with static (LDA+U) and dynamic corrections (LDA+DMFT) for on-site electron correlations. The electronic structure strongly depends on the level of approximation for correlation effects. The exchange interactions between Pu 5f electrons and the Kondo screening strength were estimated and compared, which provide a new insight to Pu magnetism.

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