Mn²⁺ electron paramagnetic resonance study of a sodium borosilicate glass prepared by the sol-gel method

Sodium borosilicate glasses were prepared by the sol-gel method and doped with a paramagnetic manganese probe. X-band electron paramagnetic resonance (EPR) experiments, carried out on powdered samples, showed that even for molar ratios higher than 10%, manganese can be inserted in the glass. EPR results obtained on different doped silica glasses showed that the ability of Mn²⁺ to be inserted in the glassy network is connected with the presence of alkali species. The bulk location of the probe was confirmed by ²⁹Si nuclear magnetic resonance investigations. EPR results indicated that manganese is located in distorted sites in an octahedral silica environment.