Fracto- and photoluminescence of quartz during its fracture

The fractoluminescence (FL) spectra at the destruction of the quartz surface by “micro-cutting” of diamond micro crystals and impact on its surface with a steel striker and photoluminescence (PL) spectra after “micro-cutting” are obtained. Band of 2.12 eV in the FL spectra was attributed to excited $\equiv$ Si-O$^\bullet$ radicals. FL consist from a set of signals whose duration was $\sim$ 50 ns, and their intensity varies by an order of magnitude. The time interval between the signals varies from $\sim$ 0.1 to several $\mu$s. Signals generated at impact contain five, and at “micro-cutting” contain four superimposed maxima. It is assumed that the FL signals appear when the barriers that prevent the movement of dislocations along the sliding planes breaks, and the smallest “primary” cracks are formatted. The rate constants of growth the cracks and fading of FL after the cracks stops are determined. The average size of the “primary” cracks surfaces after impact is $\sim$ 5 nm$^2$, and after “micro-cutting” is $\sim$ 25 nm$^2$. In the PL spectra after the fracture, a band of 2.4 eV was observed, which is attributed to non excited $\equiv$ Si-O- radicals on the cracks surface after their stop.