Positron Lifetimes in Oxides

Abstract

Lifetime spectra of positrons is oxides were measured. Densities of oxygen ions corrected for the ionicities are rather good parameters describing τ₁⁻¹ and thus positrons may be itinerant in oxides. The annihilation rates τ₁⁻¹ are about 1.5 times as large as those which are calculated on the assumption that the positrons distribute homogeneously.