par Van Petegem, Steven;Segers, Danny;Dauwe, Ch;Dalla Torre, Florian;Van Swygenhoven, Helena;Yandouzi, M.;Schryvers, Dominick;Van Tendeloo, Gustaaf;Kurinczuk, Jennifer J.;Hou, Marc 
;Zhurkin, Eugeni
Référence Materials Research Society symposia proceedings, 634
Publication Publié, 2001
;Zhurkin, EugeniRéférence Materials Research Society symposia proceedings, 634
Publication Publié, 2001
Article révisé par les pairs
| Résumé : | Positron lifetime spectroscopy is an effective tool to study various types of defects in materials including nanostructured ones. The size of free volumes associated with defects can be estimated using the lifetime components found in the measured spectra. Positron lifetime experiments are performed on nanocrystalline Ni-Al samples synthesized by the inert-gas condensation technique. The samples are further characterized by means of X-ray diffraction, electron diffraction and microscopy techniques as well as density measurements. In the lifetime spectra we observe three lifetime components corresponding to different annihilation sites in the samples. These lifetimes are compared with the results of simulations of positron lifetimes in modeled Ni-Al samples obtained using molecular dynamics and Monte Carlo calculations. Finally, we present positron lifetime results for nanocrystalline Ni3Al samples which were produced or annealed at different temperatures. © 2001 Materials Research Society. |
