LiFe5O8 and BaFe12O19 Fine Particles Crystallised in a Glassy Matrix

We investigated the magnetic and microstructure properties of the Fe₂O₃ - Li₂O - B₂O₃ and Fe₂O₃ - BaO - B₂O₃ - Sb₂O₃ glass strips (with dimensions 50 mm long, 6 mm wide and about 30-100 mikrometer thick) subjected to various heat treatments. The irreversible structure changes produced by heat treatments, were investigated by X-ray diffraction and magnetic measurements. The magnetic behaviour is discussed in terms of the evolution of the size of LiFe₅O₈ and BaFe₁₂O₁₉ crystals dispersed in the glassy matrix, with thermal annealing.