STRUCTURAL AND MAGNETIC INVESTIGATIONS OF OXIDE SOLID SOLUTION .3. MANGANESE OXIDE IN MAGNESIUM OXIDE

Lattice parameter variation of MgO due to addition up to 5% atomic of manganese oxide and manganese oxide and lithium oxide in oxidizing and reducing atmosphere have been investigated. Magnetic susceptibilities in the range 98 to 298°K have been measured. The results show that in air a limited amount of Mn2+ ions are incorporated in the MgO lattice, whilst the majority of manganese forms with MgO the Mg6MnO8 phase. Addition of lithium enables manganese ions to enter into solid solution as Mn3+ and/or Mn4+ ions depending on [Li]/[Mn] ratio. Specimens treated at 1000°C with oxygen-containing hydrogen show formation of solid solutions MgO—MnO, plus a small amount of Mg6MnO8. In samples containing lithia, the same effect of formation of Mn3+, as observed in specimens prepared in air, occurs. The stabilization of different manganese valencies by means of lithia is discussed. © 1968, Walter de Gruyter. Alle Rechte vorbehalten.