BGO glasses: structural and optical characterization

Abstract

Mixtures of 30% Bi 2 O 3 and 70% GeO 2 (in molar percents) were prepared followed by the solid state reaction at 700 o C for 30 min. or 24 h using an Al 2 O 3 crucible. After melting at 1050 o C for 10 min. the melt was poured into a preheated graphite plate and then naturally cooled to room temperature (RT). X-ray diffraction measurements (XRD) on the resulting BGO glasses have been performed, and optical absorption spectra recorded at room temperature on the samples obtained using various preparation conditions.

Eulityte glasses – synthesis and characterization

“…If such structural changes take place on a temperature interval, the permittivity increase can be considered: (1) = 0.85 kcal/mol at 150 o C. In the region (2) the estimated energy ΔE 2 is much smaller than the thermal energy RT (2) ≈ 0.6 kcal/mol (around 25 o C). It is quite obvious that in this temperature range we have a "normal" temperature dependence of permittivity, while in the temperature range (1), the mobility of clusters or other structural units increase the permittivity.…”

“…Then both the mixtures have been rapidly heated to 1050 o C for 5 ÷ 10 min. The resulting melts have been poured onto preheated graphite plate at different temperatures, below the glass transition temperature (T g ), covered with an lid and then natural slow cooled in the air till the room temperature [2].…”

“…These materials have both characteristics of glasses and crystals and combine the best properties or advantages of each of these two phases, [2].…”

Electrolytic coloration and spectral properties of OH−- and Cu+-codoped NaCl crystals

“…The V 2 or V 3 color center migrates through the diffusion of the interstitial halogen atoms in the V 2 or V 3 color center. In the electrolytic coloration of the KCl:Tl + +Ca 2+ crystals, the high concentrations of the {Tl 0 +V K } pairs were easily obtained, which resulted in more efficient coloration of the crystals [14]. Therein, the V K color centers recombined efficiently with the Tl 0 and F color centers during the thermal procedure of the thermoluminescence.…”

Characterization of BGO glass–ceramic materials

“…Glass-ceramics, obtained by the controlled crystallization of a fraction of glasses, have represented for a long time a new direction in the field of materials technology as an alternative of crystals [1][2][3]. Their structural properties are a new field which has been poorly explored and exploited.…”