Positive-ion emission from the fracture of fused silica

Positive-ion emission was observed during and after the fracture of fused silica using time-of-flight techniques and quadrupole mass spectroscopy. Emissions attributed to Si+, SiO+, and Si2O+ were observed during the fracture event itself. An emission mechanism for the silicon-containing ions is proposed involving the mechanical scission of at least three of the bonds joining a silica tetrahedron to the rest of the silica network. The production of silicon-containing ions suggests the activity of nonequilibrium processes which may contribute significantly to the fracture energy of fused silica. A long-lived emission was attributed to the electron stimulated desorption of O+.