Conversion of Ag0 into Ag2+ in [gamma]-Irradiated Organic Solid Solutions at 77 K as Studied by ESR

Ethanol and 2-methyltetrahydrofuran (MTHF) solutions of silver perchlorate were irradiated with γ-rays at 77 K. Two kinds of silver atoms (Ag0) and a small amount of dimer cations (Ag2+) were formed in both solids immediately after irradiation. On storing at 77 K, both Ag0 species reacted with Ag+ to form Ag2+ in ethanol, while in MTHF only the minor Ag0 species reacted, resulting in less growth of Ag2+ yield than in ethanol. The mechanism for the formation of Ag2+ has been discussed in terms of thermal diffusion and quantum tunneling.