EPR and magnetic susceptibility studies of iron ions in ZnO–Fe2O3–SiO2–CaO–P2O5–Na2O glasses

Room temperature electron paramagnetic resonance (EPR) spectra and temperature dependent magnetic susceptibility data have been obtained on bulk x(ZnO,Fe2O3)(65−x)SiO220(CaO, P2O5)15Na2O (6≤x≤21 mole%) glasses prepared by melt quenching method. EPR spectra of the glasses revealed absorptions centered at g≈2.1 and 4.3. The variations of the intensity and line width of these absorption lines with composition have been interpreted in terms of the variation in the concentration of the Fe2+ and Fe3+ ions in the glass and the interaction between the iron ions. EPR and magnetic susceptibility data of the glasses reveal that both Fe2+ and Fe3+ ions are present in the glasses, with their relative concentration being dependent on the glass composition. The studies reveal superexchange type interactions in these glasses, which are strongly dependent on their iron content.