Effect of iron oxide addition on structural properties of calcium silico phosphate glass/glass-ceramics

摘要

Glasses with nominal composition 34SiO _2-(45 - x) CaO-16 P _2O _5-4.5 MgO-0.5 CaF _2-x Fe _2O _3 (where x = 5, 10, 15, 20 wt.%) have been synthesized by melt quench technique. These have been investigated for structural features by using Fourier transform infra-red (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Results have shown an increase in fraction of non-bridging oxygen in glasses with an increase in iron oxide content up to 15 wt.% and subsequently decreases with further increase in iron oxide content to 20 wt.%. These effects are originated by the incorporation of Fe _2O _3 into the silica network. Iron oxide behaves as a network modifier at low concentration and stabilizes the glass network at higher content. The glass-ceramics exhibit an increase in the formation of magnetite phase with an increase in iron oxide. The glass phase in the glass-ceramics matrix, controls the surface dissolution, which in turn decides the response of the material in-vitro. The glass-ceramics with 15 wt.% iron oxide has shown optimum response in simulated body fluid.