FTIR and EPR spectroscopic investigation of calcium-silicate glasses with iron and dysprosium

• Sol–gel derived SiO2–CaO–Fe2O3–Dy2O3 amorphous matrix partially crystallized.
• CaSiO3, Fe2O3 and Fe3O4 phases are developed after heat treatment at 1200 °C.
• The amorphous phase sinks to 1/3 after 800 °C and to 1/5 after 1200 °C treatments.
• Iron ions are disposed in randomly oriented magnetite–maghemite nanoparticles.
• The developed crystalline phases are desirable in glass–ceramic biomaterials.

The sol–gel derived 50SiO2⋅30CaO⋅10Fe2O3⋅10Dy2O3 system was subjected to heat treatments at 500, 800 and 1200 °C in order to obtain crystalline phases of interest for biomedical applications. The structural changes were investigated by Fourier transform infrared spectroscopy (FTIR) and electron paramagnetic resonance (EPR). Both FTIR and EPR results support the development of wollastonite, hematite and magnetite crystalline phases desirable for samples bioactivity and heating possibility for hyperthermia treatment. Dysprosium addition was considered for subsequent radioactivation of the samples that could extend their application to thermoradiotherapy.