Prediction of Excess Free Energy from Excess Enthalpy and Excess Volume Data for Hydrocarbon Mixtures

1973 ◽  
Vol 12 (3) ◽  
pp. 372-376 ◽  
Author(s):  
Donald J. Stookey ◽  
Buford D. Smith
Keyword(s):  
Free Energy ◽  
Excess Volume ◽  
Excess Enthalpy ◽  
Excess Free Energy ◽  
Volume Data ◽  
Hydrocarbon Mixtures

Finite temperature structure and thermodynamics of the Au Σ5 (001) twist boundary

1990 ◽  
Vol 5 (11) ◽  
pp. 2663-2676 ◽  
Author(s):  
R. Najafabadi ◽  
D. J. Srolovitz ◽  
R. LeSar
Keyword(s):  
Free Energy ◽  
Grain Boundary ◽  
Specific Heat ◽  
Excess Volume ◽  
Coefficient Of Thermal Expansion ◽  
Excess Free Energy ◽  
Boundary Structure ◽  
Temperature Structure ◽  
Twist Boundary ◽  
Eam Potential

The structure and thermodynamic properties of a Σ5 (001) twist boundary in gold are studied as a function of temperature. This study was performed within the framework of the Local Harmonic (LH) model and employed an Embedded Atom Method (EAM) potential for gold. We find that for the Σ5 (001) twist boundary in gold, a distorted CSL structure is stable at low temperatures, but undergoes a phase transformation to a DSC related structure near room temperature. This transformation is shown to be first order. The temperature dependences of the excess grain boundary free energy, enthalpy, entropy, specific heat, and excess volume are calculated. Discontinuities are observed in the slope of the grain boundary excess free energy (versus temperature), in the value of the grain boundary excess specific heat and excess volume. The stable high temperature grain boundary structure has a smaller excess volume than does the lower temperature structure, and both structures have a coefficient of thermal expansion which is in excess of that for the perfect crystal.

Characterization of Textured Aluminum Lines and Modelling of Stress Voiding

1994 ◽  
Vol 343 ◽  
Author(s):  
S.C. Wardle ◽  
B.L. Adams ◽  
C.S. Nichols ◽  
D.A. Smith
Keyword(s):  
Free Energy ◽  
Excess Free Energy ◽  
Mean Field ◽  
High Energy ◽  
Polycrystalline Structure ◽  
Field Approach ◽  
Bamboo Structure ◽  
Automated Technique ◽  
Theory And Modeling

ABSTRACTIt is well known from studies of individual interfaces that grain boundaries exhibit a spectrum of properties because their structure is misorientation dependent. Usually this variability is neglected and properties are modeled using a mean field approach. The limitations inherent in this approach can be overcome, in principle, using a combination of experimental techniques, theory and modeling. The bamboo structure of an interconnect is a particularly simple polycrystalline structure that can now be readily characterized experimentally and modeled in the computer. The grain misorientations in a [111] textured aluminum line have been measured using the new automated technique of orientational imaging microscopy. By relating boundary angle to diffusivity the expected stress voiding failure processes can be predicted through the link between misorientation angle, grain boundary excess free energy and diffusivity. Consequently it can be shown that the high energy boundaries are the favored failure sites thermodynamically and kinetically.

Higher Order Conditional Probabilities and Thermodynamics of Binary Molten Alloys

1997 ◽  
Vol 11 (02n03) ◽  
pp. 93-106 ◽  
Author(s):  
O. Akinlade
Keyword(s):  
Free Energy ◽  
Experimental Evidence ◽  
Cluster Model ◽  
Excess Free Energy ◽  
Higher Order ◽  
Thermodynamic Quantities ◽  
Equiatomic Composition ◽  
Conditional Probabilities ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

The recently introduced four atom cluster model is used to obtain higher order conditional probabilities that describe the atomic correlations in some molten binary alloys. Although the excess free energy of mixing for all the systems studied are almost symmetrical about the equiatomic composition, most other thermodynamic quantities are not and thus, the study enables us to explain the subtle differences in their physical characteristics required to describe the mechanism of the observed strong heterocoordination in Au–Zn or homocoordination in Cu–Ni within the same framework. More importantly, we obtain all calculated quantities for the whole concentration range thus complimenting experimental evidence.

Partial molar volumes of aqueous 1:1 and 2:1 electrolytes and a structure model

1976 ◽  
Vol 54 (5) ◽  
pp. 824-832 ◽  
Author(s):  
Lowell W. Bahe ◽  
Kathryn A. Jung
Keyword(s):  
Free Energy ◽  
Energy Equation ◽  
Partial Molar Volumes ◽  
Quantitative Agreement ◽  
Structure Model ◽  
Volume Data ◽  
Molar Volumes ◽  
A Value ◽  
Direct Measurements ◽  
Gradient Forces

An expression for partial molar volumes is derived from the free energy equation based on field-dielectric-gradient forces, as well as coulombic forces, between ions in structured solution. Qualitative agreement between the model and experimental partial molar volume data is very good. Excellent quantitative agreement is obtained by adopting for a universal parameter of the theory a value that implies [Formula: see text] for water at 25 °C and 1 atm. The latter value is compatible with data obtained from direct measurements.

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