Abstract
We studied the electrical conductivity of LiF crystals doped with positive divalent ions. The current carriers are the positive ion vacancies created either by thermal agitation or in compensation for charge excess of a M{sup 2+} in substitution. The vacancies displacement is represented by: {mu} K'/NeT exp(- u/kT), where K' and u are constants. The concentration of free carriers equals that of the M{sup 2+} impurity only at high temperature. The M{sup 2+} ions are slightly soluble and form either precipitates of MF{sub 2} or dipole agglomerates. In these states, the M{sup 2+} ions do not contribute to the conductivity. The vacancies induced by the isolated M{sup 2+} ions are not totally free but are in equilibrium with electrically neutral dipoles: M{sub dipole} [+] {r_reversible} M{sup 2+} + [+]{sub porteur}, and follow: p/(1-p){sup 2} = Z c exp H/kT, where p is the degree of association of vacancies, Z is the number of equivalent positions of a complex, H its binding energy. The analogy with concentrated electrolyte permits to adapt Debye-Huckel theory to the crystals. In our case H varies with concentration between 0.38 and 0.07 eV. This explains both association degree equals unity at low temperature and complete dissociation
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Adam-Benveniste, M
[1]
- Commissariat a l'Energie Atomique, 91 - Saclay (France). Centre d'Etudes Nucleaires
Citation Formats
Adam-Benveniste, M.
Study of the electrical conductivity of lithium fluoride; Etude de la conductibilite electrique du fluorure de lithium.
France: N. p.,
1967.
Web.
Adam-Benveniste, M.
Study of the electrical conductivity of lithium fluoride; Etude de la conductibilite electrique du fluorure de lithium.
France.
Adam-Benveniste, M.
1967.
"Study of the electrical conductivity of lithium fluoride; Etude de la conductibilite electrique du fluorure de lithium."
France.
@misc{etde_20523404,
title = {Study of the electrical conductivity of lithium fluoride; Etude de la conductibilite electrique du fluorure de lithium}
author = {Adam-Benveniste, M}
abstractNote = {We studied the electrical conductivity of LiF crystals doped with positive divalent ions. The current carriers are the positive ion vacancies created either by thermal agitation or in compensation for charge excess of a M{sup 2+} in substitution. The vacancies displacement is represented by: {mu} K'/NeT exp(- u/kT), where K' and u are constants. The concentration of free carriers equals that of the M{sup 2+} impurity only at high temperature. The M{sup 2+} ions are slightly soluble and form either precipitates of MF{sub 2} or dipole agglomerates. In these states, the M{sup 2+} ions do not contribute to the conductivity. The vacancies induced by the isolated M{sup 2+} ions are not totally free but are in equilibrium with electrically neutral dipoles: M{sub dipole} [+] {r_reversible} M{sup 2+} + [+]{sub porteur}, and follow: p/(1-p){sup 2} = Z c exp H/kT, where p is the degree of association of vacancies, Z is the number of equivalent positions of a complex, H its binding energy. The analogy with concentrated electrolyte permits to adapt Debye-Huckel theory to the crystals. In our case H varies with concentration between 0.38 and 0.07 eV. This explains both association degree equals unity at low temperature and complete dissociation for high concentration at high temperature. (author) [French] Nous etudions la conductibilite electrique des monocristaux de LiF dopes en ions divalents positifs. Le porteur de courant est la lacune de lithium creee soit par agitation thermique, soit pour compenser l'excedent de charge d'un ion M{sup 2+} en substitution. Le deplacement des lacunes se traduit par: {mu} = K'/NeT exp(- u/kT), ou K' et u sont des constantes. La concentration des porteurs n'est egale a celle des impuretes M{sup 2+} qu'a haute temperature. Les ions M{sup 2+} sont peu solubles et forment soit des precipites de MF{sub 2}, soit des agglomerats de dipoles. Dans ces etats, les M{sup 2+} ne participent plus a la conductibilite. Les lacunes induites par les ions M{sup 2+} isoles et en substitution se presentent sous deux etats en equilibre: M{sub dipole} [+] {r_reversible} M{sup 2+} + [+]{sub porteur}, soit: p/(1-p){sup 2} = Z c exp H/kT, ou p c est la concentration de complexe, Z son nombre de position equivalente, H son energie de liaison. L'analogie du milieu avec un electrolyte concentre permet d'adapter aux cristaux la theorie de Debye-Huckel. Dans notre cas H varie avec la concentration entre 0.38 et 0.07 eV. Ceci explique un taux d'association egal a un a basse temperature et une dissociation totale pour des concentrations et des temperatures elevees. (auteur)}
place = {France}
year = {1967}
month = {Jun}
}
title = {Study of the electrical conductivity of lithium fluoride; Etude de la conductibilite electrique du fluorure de lithium}
author = {Adam-Benveniste, M}
abstractNote = {We studied the electrical conductivity of LiF crystals doped with positive divalent ions. The current carriers are the positive ion vacancies created either by thermal agitation or in compensation for charge excess of a M{sup 2+} in substitution. The vacancies displacement is represented by: {mu} K'/NeT exp(- u/kT), where K' and u are constants. The concentration of free carriers equals that of the M{sup 2+} impurity only at high temperature. The M{sup 2+} ions are slightly soluble and form either precipitates of MF{sub 2} or dipole agglomerates. In these states, the M{sup 2+} ions do not contribute to the conductivity. The vacancies induced by the isolated M{sup 2+} ions are not totally free but are in equilibrium with electrically neutral dipoles: M{sub dipole} [+] {r_reversible} M{sup 2+} + [+]{sub porteur}, and follow: p/(1-p){sup 2} = Z c exp H/kT, where p is the degree of association of vacancies, Z is the number of equivalent positions of a complex, H its binding energy. The analogy with concentrated electrolyte permits to adapt Debye-Huckel theory to the crystals. In our case H varies with concentration between 0.38 and 0.07 eV. This explains both association degree equals unity at low temperature and complete dissociation for high concentration at high temperature. (author) [French] Nous etudions la conductibilite electrique des monocristaux de LiF dopes en ions divalents positifs. Le porteur de courant est la lacune de lithium creee soit par agitation thermique, soit pour compenser l'excedent de charge d'un ion M{sup 2+} en substitution. Le deplacement des lacunes se traduit par: {mu} = K'/NeT exp(- u/kT), ou K' et u sont des constantes. La concentration des porteurs n'est egale a celle des impuretes M{sup 2+} qu'a haute temperature. Les ions M{sup 2+} sont peu solubles et forment soit des precipites de MF{sub 2}, soit des agglomerats de dipoles. Dans ces etats, les M{sup 2+} ne participent plus a la conductibilite. Les lacunes induites par les ions M{sup 2+} isoles et en substitution se presentent sous deux etats en equilibre: M{sub dipole} [+] {r_reversible} M{sup 2+} + [+]{sub porteur}, soit: p/(1-p){sup 2} = Z c exp H/kT, ou p c est la concentration de complexe, Z son nombre de position equivalente, H son energie de liaison. L'analogie du milieu avec un electrolyte concentre permet d'adapter aux cristaux la theorie de Debye-Huckel. Dans notre cas H varie avec la concentration entre 0.38 et 0.07 eV. Ceci explique un taux d'association egal a un a basse temperature et une dissociation totale pour des concentrations et des temperatures elevees. (auteur)}
place = {France}
year = {1967}
month = {Jun}
}