EPR and magnetic susceptibility studies of manganese ions in 70TeO2·25B2O3·5SrO glass matrix

EPR and magnetic susceptibility measurements have been performed on xMnO·(100 − x) [70TeO2·25B2O3·5SrO] glasses with 0.1 ≤ x ≤ 50 mol%. The number of isolated Mn2+ ions, participating at the geff ≈ 4.3 resonance increases up to 1 mol% MnO and after that decreases to nil for 10 mol% MnO. The number of Mn2+ ions participating at the geff ≈ 2.0 resonance increases when the MnO content rises. From line-width composition dependence of these glasses, for x ≥ 1 mol%, the manganese ions participate to the superexchange-magnetic interaction. Data obtained from magnetic susceptibility measurements confirm the obtained results from EPR for participation of manganese ions at the superexchange-magnetic interaction. Also, these data evidenced that in studied glasses with x > 1 mol% the manganese ions are in (2+) and (3+) valence states. The molar fractions of these ions increase with MnO content in the glasses.