PARAMAGNETIC CENTERS IN GAMMA IRRADIATED (RaO)x(SiO2)y SAMPLES WITH ADSORBED WATER

The - irradiated 77K samples (RaO)x(SiO2)y with adsorbed water were studied using EPR spectroscopy, and EPR spectrum with g=2.0028 and hyperfine splitting constant A(H)=505.3 G belonging to hydrogen atoms was registered. EPR, presumably attributed to paramagnetic hole (≡Si-O)+ , electronic (≡Si-) - centers and products of their interaction with water molecules spectra was registered. It is assumed that the main part of atomic hydrogen was oxidized to the HO2 • radical, and some of the H• atoms participate in surface radiative hydrogenation reactions with the formation of hydrogen-containing radicals when irradiated samples were heated from 77 K to room temperature. It is also assumed that •OH radicals are formed on the surface of --irradiated at 77K (RaO)x(SiO2)y samples.