aInstitute of Metallurgy, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russian Federation bInstitute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russian Federation cNANOTECH Centre, Ural Federal University, Ekaterinburg, Russian Federation dInstitute of Materials Physics, Graz University of Technology, Graz, Austria
Аннотация:
A size effect in nonstoichiometric titanium monoxide TiOy and vanadium carbide VCy nanocrystals containing high concentrations of structural vacancies was detected by electron-positron annihilation. The effect consists of a considerable increase in the positron lifetime with the specific surface area. An analysis of the intensity of a long lifetime surface component in the positron annihilation spectra and the average positron lifetime for different nonstoichiometric compounds indicated a universal character of the observed size effect.