Structural and Magnetic Properties of Fe₂O₅-P₂O₅Na₂O Glasses. Part 1: Oxygen Heat Treatment
The partial crystallisation and magnetic behaviour of 43-3Fe2O3-52-7P2O5-4-0Na 2O wt% glass made into frit, fibres and beads have been investigated before and after heat treatment. The Mössbauer spectra indicated that 90% of the iron was present as iron(III) in the glass frit and fibres while the glass beads contained 50 to 70% iron(II) ions. When the glass frit or fibres were heated in oxygen, the iron(II) ions originally present, were oxidised to iron(III) ions and an amount of FePO4 crystallised from the glass. The Mössbauer spectrum of untreated glass beads contained a magnetic component attributed to crystalline magnetite, Fe3O4. Hematite, Fe2O3, was the main crystalline phase present in the glass beads after heating in oxygen. The exact crystalline phase present in the beads depended upon the relative amounts of iron(II) and iron (III) present during the crystallisation process. The magnetically ordered component in the Mössbauer spectra is attributed to magnetite and hematite in the untreated and oxygen heat treated glass beads, respectively.
A. Moguš-Milanković et al., "Structural and Magnetic Properties of Fe₂O₅-P₂O₅Na₂O Glasses. Part 1: Oxygen Heat Treatment," Physics and Chemistry of Glasses, Society of Glass Technology, Jan 1996.
Materials Science and Engineering
Article - Journal
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