Electron paramagnetic resonance and magnetic circular dichroism of Gd3 + ions in oxyfluoride glass–ceramics containing CaF2 nanocrystals

• Transparent oxyfluoride glass–ceramics with CaF2 nanocrystals have been synthesized.
• Precipitation of CaF2 crystalline phase begins after heat treatment above 650 °C.
• Magnetic resonance studies of Gd3 + ion have been carried out.
• The Gd3 + ions are located in CaF2 nanocrystals in cubic symmetry.
• The MCD–EPR signal of Gd3 + ions has been observed in glass–ceramic samples.

Magnetic resonance investigations of the Gd3 + centre structure in the oxyfluoride glass and glass–ceramics (GCs) have been carried out. The electron paramagnetic resonance (EPR) measurements showed the presence of low symmetry Gd3 + centres in the glass sample. The cubic Gd3 + centre appeared in the glass–ceramics after heat treatment of the samples at temperatures above 650 °C. The magnetic circular dichroism (MCD) measurements of both glass and glass–ceramics showed wide absorption band around 310 nm. In the GC samples MCD–EPR of the cubic Gd3 + centre has been detected.