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.

scholarly journals Thermodynamic modeling of the Na-X (X = Si, Ag, Cu, Cr) systems

2012 ◽  
Vol 48 (2) ◽  
pp. 273-282 ◽  
Author(s):  
D. Hao ◽  
M. Bu ◽  
Y. Wang ◽  
Y. Tang ◽  
Q. Gao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Thermodynamic Modeling ◽  
First Principles ◽  
Binary Systems ◽  
Experimental Information ◽  
Enthalpies Of Formation ◽  
Calphad Approach ◽  
First Principles Calculations ◽  
Self Consistent ◽  
Measured Phase

The Na-X (X = Si, Ag, Cu, Cr) systems have been critically reviewed and modeled by means of the CALPHAD approach. The two compounds, NaSi and Ag2Na, are treated as stoichiometric ones. By means of first-principles calculations, the enthalpies of formation at 0 K for the LT-NaSi (low temperature form of NaSi) and Ag2Na have been computed to be -5210 and -29821.8 Jmol-1, respectively, with the desire to assist thermodynamic modeling. One set of self-consistent thermodynamic parameters is obtained for each of these binary systems. Comparisons between calculated and measured phase diagrams show that most of the experimental information can be satisfactorily accounted for by the present thermodynamic descriptions.

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 modeling of the Sc-Zn system coupled with first-principles calculation

2012 ◽  
Vol 48 (1) ◽  
pp. 123-130 ◽  
Author(s):  
C. Tang ◽  
P. Zhou ◽  
D.D. Zhao ◽  
X.M. Yuan ◽  
Y. Tang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Phase Diagram ◽  
Thermodynamic Modeling ◽  
First Principles ◽  
Calculated Phase Diagram ◽  
First Principles Calculation ◽  
Enthalpies Of Formation ◽  
First Principles Calculations ◽  
Self Consistent ◽  
Diagram Approach

The Sc-Zn system has been critically reviewed and assessed by means of CALPHAD (CALculation of PHAse Diagram) approach. By means of first-principles calculation, the enthalpies of formation at 0 K for the ScZn, ScZn2, Sc17Zn58, Sc3Zn17 and ScZn12 have been computed with the desire to assist thermodynamic modeling. A set of self-consistent thermodynamic parameters for the Sc-Zn system is then obtained. The calculated phase diagram and thermodynamic properties agree well with the experimental data and first-principles calculations, respectively.

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.

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.

The structural stabilities of the intermetallics and the solid-state phase transformations induced by lattice vibration effects in the Al–Zr system by first-principles calculations

2010 ◽  
Vol 25 (9) ◽  
pp. 1689-1694 ◽  
Author(s):  
Hui Zhang ◽  
Shaoqing Wang
Keyword(s):  
Solid State ◽  
Phase Transformations ◽  
High Temperatures ◽  
First Principles ◽  
Lattice Vibration ◽  
Enthalpies Of Formation ◽  
Phase Transformation Temperature ◽  
First Principles Calculations ◽  
Experimental Phase Diagram ◽  
Good Agreement

We investigated the structural stabilities of the intermetallics and the solid-state phase transformations induced by lattice vibration effects in the Al–Zr system by first-principles calculations. The calculated lattice parameters of all the phases and the phonon dispersion relations for pure Al and Zr are in good agreement with the experimental data. AlZr(oC8), Al4Zr5 (hP18), and Al3Zr5 (tI32) are predicted to be the high-temperature phases. To study the structural stabilities at high temperatures, the thermodynamic properties of the intermetallics are calculated via the linear response approach within the harmonic approximation. Thanks to the calculated enthalpies of formation at high temperatures, Al3Zr5 is predicted to be stabilized above 1163 K with respect to AlZr2 and Al2Zr3, in good agreement with the phase transformation temperature (1273 K) in the experimental phase diagram.

Solid–aqueous equilibrium in the BaSO4–RaSO4–H2O system: First-principles calculations and a thermodynamic assessment

2013 ◽  
Vol 122 ◽  
pp. 398-417 ◽  
Author(s):  
V.L. Vinograd ◽  
F. Brandt ◽  
K. Rozov ◽  
M. Klinkenberg ◽  
K. Refson ◽  
...  
Keyword(s):  
First Principles ◽  
Thermodynamic Assessment ◽  
First Principles Calculations

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.

Thermodynamic Analysis of Steels by Incorporating First-Principles Calculations into the CALPHAD Approach

2007 ◽  
Vol 539-543 ◽  
pp. 2413-2418 ◽  
Author(s):  
Hiroshi Ohtani ◽  
N. Hanaya ◽  
Mitsuhiro Hasebe
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Analysis ◽  
First Principles ◽  
Experimental Information ◽  
Full Potential ◽  
Calphad Approach ◽  
First Principles Calculations ◽  
Plane Wave Method ◽  
Ternary Phase Diagrams ◽  
High Degree

A thermodynamic analysis of the Fe−M−P (M = Nb, Ti) ternary system has been performed by combining first-principles calculations with the CALPHAD approach. Because of the lack of experimental information available, thermodynamic properties of orthorhombic anti-PbCl2-type FeMP were evaluated using the Full Potential Linearized Augmented Plane Wave method, and the estimated values were introduced into a CALPHAD-type thermodynamic analysis. Applying this procedure, the phase diagrams of the Fe−M−P ternary phase diagrams whose contents are uncertain so far were calculated with a high degree of probability. Phase diagrams for high-purity ferritic stainless steels obtained following the same procedure are also presented.

Sign in / Sign up

Export Citation Format

Share Document