Research on Magnetic properties of SiO2 - Fe2O3 - Na2O - B2O3 nano glass ceramics with Cr2O3 as nucleating agent

In this research, first of all, two samples of glasses of 40SiO2–28.6B2O3–24.5Fe2O3– 6.4Na2O–0.5Cr2O3 (mol%) (chr('39')Achr('39') sample) and 36SiO2–10.3B2O3–17Fe2O3–36Na2O–0.7Cr2O3 (mol%) (chr('39')Bchr('39') sample) were synthesized using melting furnace method. Structural and magnetic properties of the samples have been studied by the X-ray diffraction (XRD) and the vibrating sample magnetometer (VSM) respectively. X-ray diffraction pattern of the chr('39')Achr('39') sample showed formation of magnetite phase and for the chr('39')Bchr('39') sample showed amorphous phase. VSM showed ferrimagnetic properties for the chr('39')Achr('39') sample, and superparamagnetic properties for the chr('39')Bchr('39') sample. Crystallization temperature of the chr('39')Bchr('39') sample obtained at 720°C using the differential thermal analysis (DTA) This glass sample heat treated at 720 °C and 860 °C for one hour in air atmosphere and they called chr('39')B1chr('39') and chr('39')B2chr('39') respectively. The XRD pattern of the chr('39')B1chr('39') sample showed formation of maghemite and hematite phase. Magnetic hysteresis loop showed saturation magnetization (Ms) about 13.5 emu g-1 for the chr('39')B1chr('39') sample. For the chr('39')B2chr('39') sample, formation of hematite phase and Fe21.34O32 was observed using XRD data. The remanence magnetization (Mr) obtained about 0.03 emu g-1 for the chr('39')B2chr('39') sample. Fourier transform infrared spectroscopy (FTIR) showed absorption peaks of Fe-O link in 571 cm-1 and 435 cm-1 for the chr('39')B1chr('39') sample and 510 cm-1 and 461 cm-1 for the chr('39')B2chr('39') sample.