Étude des défauts ponctuels dans le niobium

2014 High purity niobium was produced by the zone melting technique and then annealed in ultra high vacuum. The purity was monitered by resistivity measurements at 4 °K and by activation analysis. Electron irradiation studies were then made on the niobium at very low temperatures. Measurements of the resistivity recovery were carried out with the object of determining a model which describes the process of annihilation and agglomeration of the radiation induced defects. A compartive study with other b. c. c. metals (Fe and Mo) leads to the acceptance of the hypothesis of an intrinsic interstitial migrating at low temperature. This permits the refection of the hypothesis of a second type of intrinsic interstitial mobile at ambient temperatures. Study of the interaction of the intrinsic defects with the impurity has been made from two viewpoints 2014 firthly modification of the defect clustering and annihilation processes and secondly trapping of the impurity by the defects. REVUE DE PHYSIQUE APPLIQUÉE TOME 5, JUIN 1970, PAGE