Investigation of Sulphur Nanoclusters in Ageing Ni-S System after Irradiation and Thermal Treatment by Positron Annihilation |
| D.A. Perminov, A.P. Druzhkov, V.L. Arbuzov and S.E. Danilov
Institute of Metal Physics, Ural Branch of Russian Academy of Science, S. Kovalevskaja Str. 18, 620990 Ekaterinburg, Russian Federation |
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| The pure Ni and Ni-S ageing systems, thermally aged and also irradiated by 5 MeV electrons at 270 K with subsequent annealing, are studied by means of positron annihilation spectroscopy. The formation of ultrafine S-rich precipitates (clusters) is observed in Ni-S during thermal ageing at about 650 K. It is assumed that these clusters do not contain vacancy-type defects and they are coherent to the Ni matrix. The positrons localize in sulphur clusters that is due to affinity-induced confinement. In irradiated Ni-S system, the mobile vacancy-S atom complexes are formed at post-irradiation annealing above 350 K (stage III). These complexes form: the three-dimensional vacancy clusters (nanovoids) decorated with S atoms. The radiation induced nucleation of S-rich clusters occurs when nanovoids dissociate. |
DOI: 10.12693/APhysPolA.125.729 PACS numbers: 81.30.Mh, 61.80.Fe, 64.75.Op |