ИСТИНА

Bismuth-germanium oxide glasses are transparent in visible and near-IR spectral regions and therefore they may be applied as matrixes for rare-earth and transition ions doping. By heat treatment, it’s possible to crystalize several phases in these glasses, namely, scintillating phase Bi4Ge3O12 and ferroelectric phase Bi2GeO5. A variation of the initial oxides ratio in glass leads to crystallization of either a single phase or several phases’ mixture. The same effect is also achieved by variation of heat treatment conditions. To obtain enhanced ferroelectric properties it’s preferably to get crystallites oriented along one direction in a glass matrix. It’s well known that textured glass-ceramic materials can be successfully produced by a laser treatment. In the present research, different composed bismuth-germanium oxide glasses doped with chromium were treated by a femtosecond Pharos SP laser (wavelength 1030 nm, pulse duration from 180 to 5000 fs, frequency repetition from 1 to 1000 kHz, maximum power 6 W). The structure and morphology of induced crystal phases as well as the laser treatment conditions affect on crystallization process were investigated by XRD and SEM.