Effective charges of oxygen ions in metal oxides

Full text: In the framework of the optical positron model with positron potential of Landau-Lifshits anion field we have obtained the new formula for definition of effective oxygen ion charges η(-e) in metal oxides from experimental values of the FWHM Γ (mrad) of the correlation curves (angular distribution) of the two-quantum positron annihilation process from bond states of positron-anion systems in crystals Γ=5.168η+7.256. The calculated values of the effective oxygen ion charges from experimental values of the FWHM Γ in more than 50 metal oxides satisfactorily coincide, in limits of dispersions of values, with η-values known from scientific literature which were calculated using non-positron methods. The laws of charge change of 'positron' effective charges in oxide number appear approximately such the same as for η-values determined by non-positron methods. The obtained values of 'positron' effective ion charges in metal oxides can be used as a handbook of η-values to solve theoretical and practical problems in solid state physics and chemistry and material science and technology