Phase formation,microstructure and electrical properties of mica glass-ceramics containing Cr2O3 produced by heat treatment

The mica glass-ceramics containing Cr₂O₃ were produced via heat treatment process from the bulk parent glass specimens. The appropriate treatment temperatures were selected according to the information provided by the DTA measurement. XRD analysis demonstrated that co-existence of the mica and MgAl₂Si₃O₁₀ phases were found at the lower treatment temperature while pure mica phase could be formed at a higher temperature. The SEM investigations revealed the effect of Cr₂O₃ addition on mica crystals development. The electrical resistivity of the glass-ceramic samples showed some significant relation with the added ions. With small amount of addition, an increase of the electrical resistivity was observed. The present glass-ceramics could be a promising candidate as advanced insulating materials, as evidenced from the presence of crystalline phases with machinable properties and good mechanical strength coupled with its high resistivity.