Electron spin resonance and magnetic studies on CaO–SiO2–P2O5–Na2O–Fe2O3 glasses

Room temperature electron spin resonance (ESR) spectra and temperature dependent magnetic susceptibility measurements have been performed to investigate the effect of iron ions in 41CaO · (52 − x)SiO2 · 4P2O5 · xFe2O3 · 3Na2O (2 ⩽ x ⩽ 10 mol%) glasses. The ESR spectra of the glass exhibited the absorptions centered at g ≈ 2.1 and g ≈ 4.3. The variation of the intensity and linewidth of these absorption lines with composition has been interpreted in terms of variation in the concentration of the Fe2+ and Fe3+ in the glass and the interaction between the iron ions. The magnetic susceptibility data were used to obtain information on the relative concentration and interaction between the iron ions in the glass.