INTERFACE REACTIONS BETWEEN GLASS MELTS CONTAINING TRANSITION-METAL OXIDES AND FERRITES

The interface reactions between SiO2-PbO-MO melts (M = Fe, Mn, Zn and Ni) and Mn-Zn and Ni-Zn ferrites were studied using electron probe mic roanalysis and X-ray diffraction. Ni ions in the glass melt containing NiO were localized at the interface between the glass and Mn-Zn ferri te. The Ni-rich layer was also detected at the interface between NiO c ontaining glass melt and Ni-Zn ferrite; the composition of this layer was thought to be close to NiFe2O4. Pb8NiSi6O21 crystal was deposited as the product of the reaction with the glass melt and Mn-Zn ferrite a t 700-degrees-C. As compared with Mn-Zn ferrite, no reaction products were formed in Ni-Zn ferrite at various temperatures. The dissolution length of Mn-Zn ferrite in SPN5 glass melt was found to be smaller tha n for other melts, and it is concluded that the NiO-rich layer at the surface of the ferrite is chemically very durable to the glass melts.