A quantitative study of the dose and impurity dependence of the defect concentrations remaining in molybdenum after 4 MeV electron irradiation at (77°K)
✍ Scribed by J.H Evans
- Publisher
- Elsevier Science
- Year
- 1970
- Weight
- 736 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0001-6160
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✦ Synopsis
Experiment81 measurements using resistivity techniques to follow the increaise of defeat concentration with eleotron irradiation dose were made on high purity molybdenum and molybdenum doped with nitrogen to two different levels. The m8rked dependence of defect concentration on impurity can be satisfactorily expl8iued by the Walker model Ii) which 8ssume~ thet the interstitial defect is mobile et the irradiation temperature and that the retention of the interstitiel depends on it being tre purity sink rctther thsn 8nnihilated 8t 8 v8c8ncy. in molybdenum at 77°K. It appears therefore th8t the interstiti81 x ped 8t an imefeet is mobile This result is in direct contrsat to th8t of de Jong and Afman") who deduced from their work that the interstitial did not become mobile until Stage HI. Evidence is presented to show that their results 8re in fact compatible with the Walker model 8nd the implication of the present work on St8ge III annealing in molybdenum is discussed. ETUDE QUANTITATIVE DES VARIATIONS AVEC LA DOSE ET LES IMPURETES DES CONCENTRATIONS DES DEFAUTS DEMEURANT DANS LE MOLYBDENE APRES IRRADIATION AUX ELECTRONS DE 4MeV A 77OK Des mesures exp&iment8les par r6sistivit6 ont 6% effeotuees aup du molybd&ne de bsute pure+5 et sur du molybdene dope 8 l'rtl;ote 8, deux concentr8tions dit%rentes, dans le but de suivre l'augmentation de 1s concentration des d&u& 8vec 18 dose d'eleotrons. L'influence marquee de l'impuret6 sur 18 conoentretion des defeuts peut Btre expliquee de faqon setisfaisante par le modele de Wslker('J qui suppose que le defaut interstitiel est mobile 8 la temperature d'irmdi8tion et que l'interstitiel ne s'8rmihile pes dsns une lacune, mais est conserve g&e 8u piegeege pss un puits d'impureti. 11 semble done que l'interstitiel est mobile dans le molybdbne 8 77°K. Ce r&ult& est en oontraste 8vec celui de de Jong et Afmsn"' qui deduisent de leur tr8v8il le f8it que l'interstitiel ne devient p8e mobile 8vant le Stsde III. L'auteur montre de faqon Bvidente que leurs r&ultats sent en f8it compatibles 8vec le mod&le de W8lker, et les implia8tions de son tr8v8il sur le recuit 8u Stade III dans le molybd&e sent disc&&s.