Influences of Fe2O3 contents on the crystallization in SiO2-Al2O3-MgO-Fe2O3-F glass systems

The influences of Fe2O3 contents on the crystallization in the SiO2-Al2O3-MgO-Fe2O3-F- glass system were investigated by using XRD and SEM techniques. The results show that the incorporation of 2.0%Fe2O3 in mass induces phase-separation of the glass and mica crystals are precipitated within the areas of the phase-separation. The mica crystals, which are confined by the sizes of phase-separative areas, exhibit rod-like shape. Increased the crystallizing temperature to 900 degrees C lead to the precipitation of needle-like mica. However, while Fe2O3 content is attained 6.0% in mass, it is suggested that iron oxide (FeFe2O4) phases be crystallized dominatedly to be main phases, but only little plate-like mica crystals are occurred.