Radiation-induced nanostructures in an iron phosphate glass

Electron and ion irradiation-induced nanostructures in an iron phosphate glass with a composition of 45 mol%Fe2O3-55 Mol%P2O5 have been characterized by advanced electron microbeam techniques. Analysis by energy-filtered transmission electron microscopy indicated that Fe-rich and P-rich nanophases were formed when the glass was irradiated under a broad (with a diameter of 1.2mum) electron beam [give the dose range]. Phase separation developed with the increase in electron dose (from 1.0 x 10(26) e/m(2) to 4.8 x 10(26) e/m(2)) as a result of the formation of an Fe-rich phase and pure P-phase. The formation of the Fe-rich and the P-phases are thought to be due to mainly ionization process. Under a low energy ion beam irradiation, Fe/FeO nanoparticles were formed, as confirmed by selected-area election diffraction analysis. However, no nanoparticles were observed under a high-energy high-dose ion irradiation. The ion beam- irradiation results suggest that the formation of the Fe/FeO nanoparticles was due to preferential sputtering during ion irradiation and that the nanoparticles lie within the surface layers of the glass.