SPECTRAL AND LUMINESCENT PROPERTIES OF CHROMIUM IONS IN FORSTERITE-LIKE NANO-GLASS CERAMICS
Read the full article
Comparative analysis of spectral and luminescent properties for glasses SiO2-Al2O3-MgO-K2O-TiO2 doped with chromium ions and forsterite nano-glass ceramic have been done. Initial glasses were obtained by using a conventional melt quenching method. Glass ceramics were produced by the two-stage secondary heat treatment of initial glasses. At the first step of the heat treatment nucleation centers were formed at 700º C. At the second step there was an increase of Mg2SiO4: Cr crystalline phase. Crystalline phase composition and the crystals size were determined by X-ray diffractometer. It is shown that the crystalline phase of Mg2SiO4 (forsterite) is precipitated during the heat treatment. Valency state and the chromium ion position in a forsterite or a glassy matrix are determined according to luminescence and absorption spectra. Identification of absorption and luminescence bands in initial and heat-treated samples is carried out. The dependence between spectral and luminescent properties of chromium and heat treatment modes is examined. The results demonstrate that ions of the trivalent and tetravalent chromium are transforming to the forsterite crystalline phase during the heat treatment, and a part of them remains in the glassy phase. Presented research results can be used for the development of glasses and nanoscale glassceramic for fiber tunable lasers and broadband optical amplifiers of a near infrared range which are used in information and telecommunication technologies.