Positron Spectroscopy group

Head: Grzegorz Karwasz

Positron annihilation spectroscopy is suitable for the investigation of the nanostructured materials as they are sensitive to defects consisting of free atoms and/or vacancies. Positron annihilation is non-destructive and allows to determine types and concentration of defects below 1 ppm. Sites favorable to trapping electrons are also favorable for positron annihilation. Positrons are unique in determining surface structure and hidden near-to surface nanoporosity through positron re-emission
This laboratory is still under construction. Positrons will be used here to detect defects in nanostructured layers and nano-porosities in all classes of materials techniques of positron lifetime measurements and positron Doppler-broadening. The results will be correlated with XRD and AFM studies. Optical studies (absorption and luminescence) will be used in search of correlation between traps as seen by positrons and electronic states in the material.