Effect of Cr2O3 on structural and magnetic properties of SiO2–B2O3–Fe2O3–Al2O3–Na2O glass–ceramics

Abstract SiO2–B2O3–Fe2O3 magnetic glass–ceramics were prepared by conventional melt quench using a heat treatment method. The effects of Cr2O3 on the phase structure and magnetic properties of the ferrimagnetic glass–ceramics were examined by differential scanning calorimetry, photothermal measurement system, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The magnetic phase of the obtained glass–ceramics was Fe3O4, and the magnetic crystal size and amount of second phase (hematite, Fe2O3) increased with increasing amount of Cr2O3 added. More importantly, the coercivity and saturation magnetization of the sample without Cr2O3 were higher than the samples containing 1–4 wt.% Cr2O3, indicating the spontaneous crystallization capacity of magnetite.