Structural, Magnetic and Antibacterial Properties of Some Biocompatible Nano-Crystalline Ferrimagnetic Glass/Glass-Ceramics

Abstract

Ferrimagnetic glass-ceramics have been prepared from three different glass compositions; (a) 34SiO2–(45−x) CaO–16P2O5–4.5MgO–0.5CaF2–xFe2O3 (x = 10–20 wt%), (b) 25SiO2–50CaO–15P2O5–(10 − x)Fe2O3–xZnO (x = 0–5 mol %) and (c) 25SiO2–(50−x)CaO–15P2O5–8Fe2O3–2ZnO−xAg (where x = 2 and 4 mol %). Structural and micro structural properties have been investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Magnetic properties were studied using vibrating sample magnetometry and Mossbauer spectroscopy. X-ray diffraction studies revealed the presence of hydroxyapatite [Ca10(PO4)6(OH)2], wollastonite [CaSiO3] and magnetite [Fe3O4] crystalline phases in the glass-ceramic samples. The microstructure revealed the formation of nano size crystallites. Magnetic studies showed the evolution of ferrimagnetic property. Increase in magnetization has been observed with an increase of ZnO up to 2 mol % and Ag content up to 4 mol %. The bioactivity of the glass-ceramics samples was investigated by examining apatite formation on the surface of the samples treated in simulated body fluid (SBF). Mossbauer spectroscopy has shown the relaxation of magnetic particles. Bioactive response in SBF was found dependent on iron oxide content. Antibacterial response of Ag containing glasses against with Escherichia coli (E. coli) was studied and found to depend on Ag ions concentration in the glass matrix. The glass samples with 4 mol % Ag have shown effective antibacterial activity against E. coli.