Published 1968 | Version v1
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Contribution to the study of point defects in uranium α

  • 1. Commissariat a l'Energie Atomique, Fontenay-aux-Roses (France). Centre d'Etudes Nucleaires

Description

Uranium quenched from temperatures as low as 100 K shows an important increase in resistivity which disappears after annealing between 4.2 K and 41 K. This phenomenon is explained by a cold-work of the metal due to the rapid traversing of the temperature region where the lattice parameters exhibit an important and anisotropic increase. The annealing occurs in two stages (4.2 K - 26 K - 41 K). Purity of samples has an influence on the phenomenon. Model proposed is confirmed by the comparison with some experiments of annealing of defects created by irradiation of uranium at very low temperatures. Vacancies have been quenched in the metal from temperatures around 650 C (limit of the α phase). The formation energy so found is EF = 0. 5 ± 0.15 eV. The annealing out of the induced resistivity happens in two stages (300-390; 420-560 C). (authors)

Availability note (English)

Available from INIS in electronic form

Abstract (French)

La trempe de l'uranium dans l'helium liquide depuis des temperatures aussi basses que 100 K entraine une augmentation de resistivite qui disparait par recuit entre 4.2 K et 41 K. Ce phenomene est interprete comme un ecrouissage du metal provoque par la traversee rapide d'une region ou les parametres cristallins varient beaucoup et de facon anisotrope. Le recuit se fait en deux stades (4.2 K - 26 K - 41 K). La purete des echantillons a une influence sur le phenomene. Le modele propose a ete verifie par comparaison avec des experiences de recuit de defauts crees par irradiation de l'uranium a tres basse temperature. Des lacunes ont ete retenues a l'etat metastable par trempe du metal depuis des temperatures voisines de 650 C (limite de la phase α). L'energie de formation trouvee est EF = 0.5 ± 0.15 eV. La guerison se fait en deux stades (300-390 C; 420-560 C). (auteurs)

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Additional details

Additional titles

Original title (French)
Contribution a l'etude des defauts ponctuels dans l'uranium α

Publishing Information

Imprint Pagination
[104 p.]
Report number
CEA-R--3526

Optional Information

Notes
62 refs.