Positron Annihilation in Amorphous, Trigonal and α-Monoclinic Selenium

Abstract
Positron lifetimes and angular correlation curves for trigonal(t), α-monoclinic(m) and amorphous(a) selenium have been measured. It has been found that differences in lifetime and angular correlation curve between m-Se and t-Se are relatively small but those between a-Se and t-Se fairly large. These changes have been qualitatively discussed in terms of changes in electron and positron state among three selenium phases.