EPR and magnetic investigations of MnO-B2O3-PbO glasses

Electron paramagnetic resonance (EPR) of Mn2+ ions revealed their distribution on different structural units of a 2B2O3PbO glass matrix doped with MnO. Octahedral symmetric sites, tetragonally distorted, were detected. The progressive clustering of manganese ions was evidenced when the MnO content increased. EPR and magnetic susceptibility data revealed that both Mn2+ and Mn3+ ions are simultaneously present in the glass matrix and the transition from isolated ions in samples with x≤1 mol % to those involved in dipole–dipole interactions for samples with x≤30 mol % and antiferromagnetically coupled ions when x>30 mol %.