Abstract
An experimental study of diffusion under a thermal gradient shows that the heat of transport Q-bar* for self-diffusion in the noble metals is very low (a few hundredths of I eV) and relatively large in Fe{alpha} (+ 1,7 {+-} 0,8 eV). The apparent heat of transport of Sb in Cu, measured by the 'thin layer technique' is -0.21 {+-}0,05 eV.The influence of the density of sources and sinks of vacancies on the observed vacancy flux is determined by a calculation involving the thermodynamics of irreversible processes; when the mean distance between sources and sinks is larger than a certain limiting value, the vacancy flux vanishes.The contribution to the heat of transport of electron-defect (q*e) and phonon-defect (q*p) collisions is calculated using a semi-classical approach and by a quantum mechanical method; q*e is related to the resistivity {delta} -{rho}{sub d} and to the thermoelectric power of the defect at its stable position and at its saddle-point. A relation between q*e and the effective valency Z* of the defect allows a determination of {delta}{sub {rho}}{sub d} at the saddle-point. Numerical values of q*e are given for some impurities in noble metals. (author) [French] L'etude experimentale de la diffusion sous gradient de temperature
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Gerl, M
[1]
- Commissariat a l'Energie Atomique, Saclay (France). Centre d'Etudes Nucleaires
Citation Formats
Gerl, M.
Contribution to the theoretical study of the thermal diffusion of point defects in metals; Contribution a l'etude theorique et experimentale de la thermodiffusion de defauts ponctuels dans les metaux.
France: N. p.,
1968.
Web.
Gerl, M.
Contribution to the theoretical study of the thermal diffusion of point defects in metals; Contribution a l'etude theorique et experimentale de la thermodiffusion de defauts ponctuels dans les metaux.
France.
Gerl, M.
1968.
"Contribution to the theoretical study of the thermal diffusion of point defects in metals; Contribution a l'etude theorique et experimentale de la thermodiffusion de defauts ponctuels dans les metaux."
France.
@misc{etde_20547173,
title = {Contribution to the theoretical study of the thermal diffusion of point defects in metals; Contribution a l'etude theorique et experimentale de la thermodiffusion de defauts ponctuels dans les metaux}
author = {Gerl, M}
abstractNote = {An experimental study of diffusion under a thermal gradient shows that the heat of transport Q-bar* for self-diffusion in the noble metals is very low (a few hundredths of I eV) and relatively large in Fe{alpha} (+ 1,7 {+-} 0,8 eV). The apparent heat of transport of Sb in Cu, measured by the 'thin layer technique' is -0.21 {+-}0,05 eV.The influence of the density of sources and sinks of vacancies on the observed vacancy flux is determined by a calculation involving the thermodynamics of irreversible processes; when the mean distance between sources and sinks is larger than a certain limiting value, the vacancy flux vanishes.The contribution to the heat of transport of electron-defect (q*e) and phonon-defect (q*p) collisions is calculated using a semi-classical approach and by a quantum mechanical method; q*e is related to the resistivity {delta} -{rho}{sub d} and to the thermoelectric power of the defect at its stable position and at its saddle-point. A relation between q*e and the effective valency Z* of the defect allows a determination of {delta}{sub {rho}}{sub d} at the saddle-point. Numerical values of q*e are given for some impurities in noble metals. (author) [French] L'etude experimentale de la diffusion sous gradient de temperature montre que la chaleur de transport d'autodiffusion des metaux nobles est tres faible (quelques centiemes d'eV), alors que celle de Fe{alpha} est relativement elevee (+1,7 {+-} 0,8 eV). La chaleur de transport apparente de Sb dans Cu, mesuree par la technique de la couche mince, est (-0.21 {+-} 0.05 eV). L'influence de la densite de sources et puits de lacunes sur le flux de lacunes observe est determinee en appliquant le formalisme de la thermodynamique des processus irreversibles; si la distance moyenne entre sources et puits excede une certaine valeur limite, le flux de lacunes devient pratiquement nul. La contribution des chocs electrons-defaut (q*e) et phonons-defaut (q*p) a la chaleur de transport,est calcul theoriquement a l'aide de deux methodes - semi-classique et quantique - complementaires; q*e est reliee a la resistivite {delta}{sub {rho}}{sub d} et au pouvoir thermoelectrique du defaut en position stable et en position de col. Une relation etablie entre q*e et la valence efficace Z* du defaut permet de determiner {delta}{sub {rho}}{sub d} en position de col. Les valeurs numeriques de q*e sont donnees pour quelques impuretes dans les metaux nobles. (auteur)}
place = {France}
year = {1968}
month = {Jan}
}
title = {Contribution to the theoretical study of the thermal diffusion of point defects in metals; Contribution a l'etude theorique et experimentale de la thermodiffusion de defauts ponctuels dans les metaux}
author = {Gerl, M}
abstractNote = {An experimental study of diffusion under a thermal gradient shows that the heat of transport Q-bar* for self-diffusion in the noble metals is very low (a few hundredths of I eV) and relatively large in Fe{alpha} (+ 1,7 {+-} 0,8 eV). The apparent heat of transport of Sb in Cu, measured by the 'thin layer technique' is -0.21 {+-}0,05 eV.The influence of the density of sources and sinks of vacancies on the observed vacancy flux is determined by a calculation involving the thermodynamics of irreversible processes; when the mean distance between sources and sinks is larger than a certain limiting value, the vacancy flux vanishes.The contribution to the heat of transport of electron-defect (q*e) and phonon-defect (q*p) collisions is calculated using a semi-classical approach and by a quantum mechanical method; q*e is related to the resistivity {delta} -{rho}{sub d} and to the thermoelectric power of the defect at its stable position and at its saddle-point. A relation between q*e and the effective valency Z* of the defect allows a determination of {delta}{sub {rho}}{sub d} at the saddle-point. Numerical values of q*e are given for some impurities in noble metals. (author) [French] L'etude experimentale de la diffusion sous gradient de temperature montre que la chaleur de transport d'autodiffusion des metaux nobles est tres faible (quelques centiemes d'eV), alors que celle de Fe{alpha} est relativement elevee (+1,7 {+-} 0,8 eV). La chaleur de transport apparente de Sb dans Cu, mesuree par la technique de la couche mince, est (-0.21 {+-} 0.05 eV). L'influence de la densite de sources et puits de lacunes sur le flux de lacunes observe est determinee en appliquant le formalisme de la thermodynamique des processus irreversibles; si la distance moyenne entre sources et puits excede une certaine valeur limite, le flux de lacunes devient pratiquement nul. La contribution des chocs electrons-defaut (q*e) et phonons-defaut (q*p) a la chaleur de transport,est calcul theoriquement a l'aide de deux methodes - semi-classique et quantique - complementaires; q*e est reliee a la resistivite {delta}{sub {rho}}{sub d} et au pouvoir thermoelectrique du defaut en position stable et en position de col. Une relation etablie entre q*e et la valence efficace Z* du defaut permet de determiner {delta}{sub {rho}}{sub d} en position de col. Les valeurs numeriques de q*e sont donnees pour quelques impuretes dans les metaux nobles. (auteur)}
place = {France}
year = {1968}
month = {Jan}
}