Structure and magnetic properties of BeO-Fe2O3-Al2O3-TeO2 glass-ceramic composites

Abstract In this work, glass-ceramics in the xBeO–20Fe2O3–(80-x)TeO2 system with x = 0–25 mol% were synthesized by the traditional melt quenching route and studied by inductively coupled plasma optical emission spectroscopy, X-ray diffraction, confocal microscopy, infrared and Raman spectroscopy. BeO addition was found to support the crystallization process of Fe2O3 during melting, and an increased BeO content was associated with an increased fraction of the crystalline Fe2O3 phase and an increased size of these crystallites. Furthermore, samples doped with BeO exhibit an increasing polymerization of the residual tellurite glass network compared to the undoped sample. The magnetic properties and specific heat of all synthesized materials were measured, and the results show that all studied samples behave as spin-glasses. Also, the Morin transition of hematite was observed at 260 K with intensity depending on the material content in Fe2O3 crystalline phase, the formation of which correlates with the amount of added BeO.