Application of positron annihilation and Raman spectroscopies to the study of perovskite type materials

Positron annihilation and Raman spectroscopies are used for studying the defect properties of perovskite type materials ([Ba.sub.3]B' [Nb.sub.2][O.sub.9] (where B' = Mg, Zn, or Co)) with near-stichiometric compositions. The existence of an internal electric field between charged 1:1 nanoregions and the rest of material has created conditions for preferential positron annihilation that affect the obtained positron lifetime values.