Anatoly N. Trukhin , Krishjanis Smits, Georg Chikvaidze, Tatiana I. Dyuzheva, Ludmila M. Lityagina
This paper compares the luminescence of different modifications of silicon dioxide – silica glass, -quartz
crystal and dense octahedron structured stishovite crystal. Under x-ray irradiation of pure silica glass and
pure -quartz crystal, only the luminescence of self-trapped exciton (STE) is detected, excitable only in
the range of intrinsic absorption. No STE luminescence was detected in stishovite since, even though its
luminescence is excitable below the optical gap, it could not be ascribed to a self-trapped exciton. Under
ArF laser excitation of pure -quartz crystal, luminescence of a self-trapped exciton was detected under
two-photon excitation. In silica glass and stishovite mono crystal, we spectrally detected mutually similar
luminescences under single-photon excitation of ArF laser. In silica glass, the luminescence of an oxygen
deficient center is presented by the so-called twofold coordinated silicon center (L.N. Skuja et al., Solid
State Commun. 50, 1069 (1984)). This center is modified with an unknown surrounding or localized
states of silica glass (A.N. Trukhin et al., J. Non-Cryst. Solids 248, 40 (1999)). In stishovite, that same
luminescence was ascribed to some defect existing after crystal growth. For -quartz crystal, similar to
silica and stishovite, luminescence could be obtained only by irradiation with a lattice damaging source
such as a dense electron beam at a temperature below 80 K, as well as by neutron or -irradiation at
290 K.
In spite of a similarity in the luminescence of these three materials (silica glass, stishovite mono crystal and
irradiated -quartz crystal), there are differences that can be explained by the specific characteristics of
these materials. In particular, the nature of luminescence excited in the transparency range of stishovite is
ascribed to a defect existing in the crystal after-growth. A similarity between stishovite luminescence and
that of oxygen-deficient silica glass and radiation induced luminescence of -quartz crystal presumes a
similar nature of the centers in those materials.
Central European Journal of Physics • 9(4) • 2011 • 1106-1113
DOI: 10.2478/s11534-011-0016-5
