Host-defect luminescence of stishovite

A detailed study of the 4.75 eV luminescence band of stishovite single crystal (SiO₂ with rutile structure) is reported. Kinetics of luminescence intensity is studied at durable (tens of minutes) X-ray excitation. The observed behaviour of the band intensity is explained by creation and destruction of luminescence centres depending on temperature both being determined by radiation stimulated diffusion of atomic particles. The luminescence decay is observed to last for minutes after X-ray irradiation while only for ns and hundreds of μs under pulsed e-beam irradiation suggesting a complicated recombination of the created defects. The UV band of stishovite is compared with the 4.9 eV luminescence band in α-quartz, which could not be created by X-ray. The latter being associated with transient centres created by destructive electron-beam irradiation or with permanent centres at neutron or γ-irradiation, and with oxygen-deficient luminescence of silica glass.