Thanks are due to Mr. J. Raadsen for his able assistance during the experiments.
The effect of non-random solute distribution around vacancies on the enhancement of solvent and solute diffusion
β Scribed by F. Faupel; Th. Hehenkamp
- Publisher
- Elsevier Science
- Year
- 1987
- Weight
- 460 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0001-6160
No coin nor oath required. For personal study only.
β¦ Synopsis
In a previous paper the enhancement of solvent and solute diffusion upon alloying was discussed at high temperatures in terms of the complex model of Dom and Mitchell and its application to diffusion by Hehenkamp et al., regarding the solute atoms as being randomly distributed around vacancies and introducing an average binding free enthalpy for each complex. In this work the effect of configuration is taken into account additionally according to B&ces and Kovacs, and different binding free enthalpies are introduced in a given complex. Modified expressions are derived for the enhancement factors of solvent and solute diffusion, and the binding free enthalpies of the different complexes and configurations are given as functions of these quantities. An approximation is developed for the calculation of the binding free enthalpy of a vacancy-impurity pair solely from the linear and second order enhancement factors of solvent diffusion. The formalism, which is no longer restricted to high temperatures, is applied to enhancement measurements in &Sn and &Sb alloys in the high temperature range. The results are compared with the previous calculations. The deviations are found to be very small. Zusammenfassung-In einer friiheren Arbeit wurde die Beschleunigung der Selbst-und Fremddiffusion mit der Zulegierung bei hohen Temperaturen im Rahmen des Komplexmodells von Dom und Mitchell und seiner Anwendung auf die Diffusion von Hehenkamp et al. diskutiert. Dabei wurden die Fremdatome als statistisch urn die Leerstellen verteilt angesehen und fur jeden Komplex eine mittlere freie Bindungsenthalpie eingefiihrt. In dieser Arbeit wird zusiitzlich gem%3 Btrces und Kovacs der Einflug der Konfiguration beriicksichtigt, und filr einen gegebenen Komplex werden verxhiedene freie Bindungsenthalpien eingefiihrt. Es werden modifizierte Ausdriicke fur die Anstiegsfaktoren der Selbst-und Fremddiffusion hergeleitet und die freien Bindungsenthalpien der unterschiedlichen Komplexe und Konfiguration als Funktionen dieser GriiBen berechnet. Es wird eine Niherung angegeben, die es gestattet, die freie Leerstelle-Fremdatom Bindungsenthalpie allein aus den linearen und quadratischen Anstiegsfaktoren der Selbstdiffusion zu berechnen. Der Formalismus, der jetzt nicht mehr nur auf hohe Temperaturen beschriinkt ist, wird auf Beschleunigungsmessungen in &Sn-und &Sb-Legierungen im Hochtemperaturbereich angewandt. Die Ergebnisse werden mit den friiheren Rechnungen verglichen. Die Abweichungen erweisen sich als sehr klein.
π SIMILAR VOLUMES
The effect of temperature on the Dimroth-Reichardt ET(30) parameter of binary mixtures of dimethyl sulfoxide, acetonitrile and nitromethane with alcohols and water was studied. The ET(30) polarity parameter of many of these binary mixtures exhibits a strong synergism. Dimethyl sulfoxide, acetonitril
To facilitate the deposition of Ξ³ -ureidopropyltrimethoxysilane monomer onto E-glass fibers, anhydrous acetone and THF were used as carrier solvents. Untreated industrial E-glass fibers and cold water plasma treated E-glass fibers were used. Cold water plasma treatment of the fibers increased the hy
The effects of ionic strength and pH on the diffusion coefficients and gross conformation of chitosan molecules in solution were studied. Chitosan with 83% degree of deacetylation (DD) was prepared from red shrimp (Solemocera prominenitis) processing waste. Ten different molecular weight chitosans w
## Abstract Advective solute travel times and their distributions in hydrological catchments are useful descriptors of the dynamics and variation of the physical mass transport among and along the different sourceβtoβrecipient pathways of solute transport through the catchments. This article invest