scholarly journals Calculation of diffusion coefficients in ternary systems from diaphragm cell experiments

1969 ◽  
Vol 73A (1) ◽  
pp. 43 ◽  
Author(s):  
P.R. Patel ◽  
E.C. Moreno ◽  
T.M. Gregory
Keyword(s):  
Diffusion Coefficients ◽  
Ternary Systems ◽  
Diaphragm Cell

A PROCEDURE TO DETERMINE THE SEGREGATION PARAMETERS IN TERNARY SYSTEMS FROM EXPERIMENTAL DATA OF A LINEAR TEMPERATURE RUN

2007 ◽  
Vol 14 (04) ◽  
pp. 681-685
Author(s):  
W. D. ROOS ◽  
J. K. O. ASANTE
Keyword(s):  
High Temperature ◽  
Temperature Region ◽  
Diffusion Coefficients ◽  
High Speed ◽  
Ternary Systems ◽  
Equilibrium Temperature ◽  
Rate Equations ◽  
Interaction Coefficients ◽  
Linear Temperature ◽  
Good Set

Profiles of surface concentrations as a function of temperature, where the temperature is increased at a constant rate, contain the necessary information to extract segregation parameters. A model using rate equations can be used to simulate these profiles. Even on a high-speed computer, solving these equations can take hours. For ternary and higher component alloys the fit parameters are at least nine and finding the best fit manually can extend the search to days. Theoretical segregation and diffusion models show two temperature regions of interest. In the low-temperature region, representing the kinetics of segregation, the diffusion coefficients of the species dominate the flux of atoms to the surface, and in the high-temperature region the surface concentrations are independent of the diffusion coefficients. In the high-temperature equilibrium region the surface concentrations are determined only by the segregation energies and interaction coefficients. A procedure is presented that can find a good set of segregation parameters within seconds. The sensitivity of selecting the kinetics, as well as the equilibrium temperature regions will be demonstrated. The procedure is used to extract the segregation parameters for a Cu (111) 0.13 at% Sn 0.18 at% Sb system.

Diffusion measurements in aqueous L-ascorbic acid solutions

1980 ◽  
Vol 33 (8) ◽  
pp. 1857 ◽  
Author(s):  
M Shamim ◽  
SMA Baki
Keyword(s):  
Ascorbic Acid ◽  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Molecular Form ◽  
Acid Solutions ◽  
Acid Molecule ◽  
Diaphragm Cell ◽  
Solvent Molecules

Diffusion coefficients in aqueous 0.05-1.0 M L-ascorbic acid solutions have been measured at 298.15 K by using a modified version of the Stokes diaphragm cell. The diffusion coefficient of un-ionized ascorbic acid molecule at zero concentration has been found to be 1.055 × 10-9 m2 s-1. The diffusion coefficient of an isolated ascorbate ion, C6H7O6-, is about 23 % lower than the molecular form; this indicates, as expected, that ions strongly interact with solvent molecules.

Equations for determining Diffusion Coefficients in Liquid Systems by the Diaphragm Cell Technique

Nature ◽  
1960 ◽  
Vol 187 (4739) ◽  
pp. 767-768 ◽  
Author(s):  
F. A. L. DULLIEN ◽  
L. W. SHEMILT
Keyword(s):  
Diffusion Coefficients ◽  
Liquid Systems ◽  
Diaphragm Cell

The Influence of Thermodynamic Properties of Alloys on Effective Interdiffusion Coefficients in Ternary Systems

2007 ◽  
Vol 263 ◽  
pp. 141-146 ◽  
Author(s):  
Ü. Ugaste ◽  
Tony Laas ◽  
T. Škled-Gorbatšova
Keyword(s):  
Thermodynamic Properties ◽  
Diffusion Coefficients ◽  
Reasonable Agreement ◽  
Ternary Systems ◽  
Tracer Diffusion ◽  
Diffusion Couples ◽  
Experimental Values ◽  
Tracer Diffusion Coefficients ◽  
Interdiffusion Coefficients ◽  
The Relationship

To prove the validity of Dayananda’s phenomenological model of interdiffusion in ternary systems the effective interdiffusion coefficients for a few diffusion couples in the system Cu-Ni-Fe, annealed at 1000 oC, are calculated on the basis of this model using available tracer diffusion and thermodynamic data. It is found that the calculated values of effective interdiffusion coefficients are in reasonable agreement with experimental values extracted independently from experimental concentration--penetration curves. Using the relationship between effective interdiffusion coefficients, tracer diffusion coefficients and thermodynamic factors, it is shown that thermodynamic properties of alloys play a significant role in interdiffusion processes in the system Cu-Fe-Ni.

Diffusion coefficients in some ternary systems

1976 ◽  
Vol 21 (4) ◽  
pp. 452-456 ◽  
Author(s):  
Jaroslav Bulicka ◽  
Jaroslav Prochazka
Keyword(s):  
Diffusion Coefficients ◽  
Ternary Systems

scholarly journals Diffusion Path in Ternary One-Phase Systems: An Overview

2020 ◽  
Vol 44 (1) ◽  
pp. 1-8
Author(s):  
D. Serafin ◽  
W. J. Nowak ◽  
P. Wierzba ◽  
S. Wędrychowicz ◽  
B. Wierzba
Keyword(s):  
Diffusion Coefficients ◽  
Ternary Systems ◽  
Diffusion Path ◽  
System Of Equations ◽  
New Materials ◽  
Intrinsic Diffusion ◽  
Full System ◽  
Initial Concentration ◽  
Phase Systems ◽  
The Difference

AbstractIn this article, the fundamental questions concerning the diffusion path, in particular, what is the shape of diffusion path in ternary systems and how to approximate it from the initial concentration profile, will be answered. The new rules were found which allow for determining the diffusion path from a known initial concentration of the components. This approximation will allow for designing new materials without a time-consuming numerical simulation of the full system of equations. It is shown that the difference in intrinsic diffusion coefficients determines the up-hill diffusion.

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