Microstructures formed during devitrification of Na_2O? Al_2O_3?B_2O_3?SiO _2?Fe_2O_3 glasses

摘要

Soda alumina borosilicate glasses of composition (24-y)Na _2O?yAl_2O_3?14B_2O _3?37SiO_2?25Fe_2O_3, y = 8, 12, 14, 16 mol%, were melted using Fe_2O_3 as raw material. Besides, samples with y = 12 and Fe_2O_3 concentrations of 14.32, 17.8, and 25.0 mol% were prepared from FeC_2O _4?2H_2O as raw material. The X-ray diffraction analyses showed the presence of magnetite for the samples from all the investigated compositions. Transmission electron microscopy (TEM) evidenced that all the samples are phase separated and droplets in the diameter range 100-1000 nm, enriched in iron, are formed. Inside these droplets, numerous small magnetite particles, with size in the 25-40 nm interval, are crystallized.