title: Interstitial OH radicals in F2-laser-irradiated bulk amorphous SiO2.
abstract: An interstitial hydroxyl radical (HO*) has been generated in bulk amorphous SiO2 (a-SiO2) loaded with interstitial H2O molecules and exposed to F2 laser light (hnu = 7.9 eV, lambda = 157 nm) at 77 K. F2 laser light dissociates an O-H bond of interstitial H2O into a pair of hydrogen atom (H0) and HO*. The resultant H0 disappears below 150 K, whereas HO* is detectable after thermal annealing at 200 K. The electron paramagnetic resonance (EPR) signal of the interstitial HO* recorded at 77 K is similar to that formed in amorphous ice, indicating that HO* is confined in an orthorhombic field by hydrogen bonding, probably with adjacent H2O molecules, silanol (SiOH) groups, and bridging oxygen atoms in the a-SiO2 network.
authors.forename: Koichi
authors.initials: K
authors.lastname: Kajihara
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hirano
authors.forename: Linards
authors.initials: L
authors.lastname: Skuja
authors.forename: Hideo
authors.initials: H
authors.lastname: Hosono