The synthesis of bioactive magnetic glass ceramics for hyperthermia treatment is still far from optimization due to the variable performance of many nanostructured systems. \({0.2}{\text{SiO}}_{{2}} {-}{0.5}{\text{FeO}}{-}{0.3}{\text{CaO}}\) glass ceramics were synthesized by sol–gel method at room temperature with a precursor to solvent ratio 1:5. The effect of adding polyethylene glycol 4000 (PEG4000) with 2, 4, 8, 12 and 16 wt% in the final stage of the sol preparation, on the magnetic and phase properties of the samples was studied. Heat treatment of the samples was done at 680 and 760°C. Phase analysis showed that maghemite and hematite phases have crystallized. By adding PEG4000 from 2 to 12 wt%, the saturation magnetization of the samples increased from 6.9 to 14.95 emu g–1. Further increase of PEG did not have much effect on improving the magnetic properties. It was also seen that heat treatment at higher temperatures led to a decrease in magnetic properties.
