EPR Study of MnO and MnO2 Doped Barium Aluminoborate Glasses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)An off-equilibrium redox condition study of Mn2+ and Mn4+ ions added to the batch is reported for the case of the preparation of the barium aluminoborate glasses, by considering that the out of equilibrium reactions started already on the melt. It is shown that for lower dopant concentrations the relative concentrations of the oxidation states of the manganese are found out of equilibrium up to the added amount of 0.3 mol% of MnO2, but on doping with MnO, the equilibrium state is achieved at the MnO added amount of 0.07 mol%. The change of the redox condition of the manganese ions toward the equilibrium was studied by tracking the Mn2+ amount as a function of the doping concentration in the two cases of MnO and MnO2.26622952298Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES