Crystallization of BaFe12O19 magnetic particles in Fe2O3–B2O3–Bi2O3–BaO–LiCl glass ceramics

The glasses with composition xFe2O3(55−x)B2O3–10Bi2O3–25BaO–10LiCl (where x = 0.0, 5.0, 7.0, 10.0, 12.0 and 15.0) are fabricated via melt-quench technique. Structural and physical properties of as-prepared and thermally treated glass samples have been explored using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and density measurements. The amorphous nature and formation of crystallites (BiB3O6 and BaFe12O19) after giving thermal treatment have been confirmed by both XRD and FTIR spectra. FTIR spectra reveal that broad peaks became sharp on thermal treatment and fraction of 4-coordinated boron atoms N4 increases for as-prepared as well as thermally treated samples as iron content increases, which suggest participation of iron ions in glass network. Variation in density and molar volume with iron content confirm modification in glass network based on ionic size of modifier. Scanning electron microscope images show formation of glass crystallites in thermally treated glass sample.