Yu. V. Marchenko

Oxyfluoride Glasses (A Review)

The influence of oxygen on the glass formation and the structure of oxyfluoride glasses has been considered using different glass systems containing fluorine and oxygen.

Synthesis and characterization of bismuth-containing oxyfluoroniobate glasses

New glasses are prepared in the MnNbOF5-BaF2-BiF3 system. The thermal parameters of these glasses are analyzed as influenced by bismuth trifluoride. IR and Raman spectroscopy shows that the glass structures are built of Nb(O, F)6 polyhedra, which are linked by oxygen bridges to form glass nets via. A medium-order order region in the glass includes fluoroniobate polyhedra not linked directly to bismuth trifluoride polyhedra. A Ba0.55Bi0.45F2.45 crystalline phase is discovered at 320°C in a glass of composition 20MnNbOF5-40BaF2-40BiF3.

Phase composition of antimony(III) oxide samples of different origin

Phase and isotope composition of a series of antimony(III) oxide samples, including those prepared by hydrolysis of antimony(III) fluoride and chloride and commercial chemicals, was determined by X-ray diffraction analysis, IR, Raman, and 121,123Sb NQR spectroscopy. Antimony(III) oxide obtained from aqueous solutions was shown to consist of valentinite or a mixture of valentinite and senarmontite.

Glass Formation in Niobium Fluoride Systems

Various variants of producing niobium fluoride glasses using niobium pentafluoride and its oxyfluoride compounds as precursors were studied.

InF3-based bismuth-containing glasses

Glasses have been prepared in the InF3-BiF3-BaF2-PbF2-ZnF2-LnF3 (Ln = Eu, Tm) system. The short-range and medium-range order structure of the glass network is discussed on the basis of IR and Raman spectroscopy data. The effect of bismuth trifluoride on the thermal properties, structure, and photo-luminescence properties of glasses was studied. Bismuth trifluoride doping improves the thermal parameters of glasses. The polyhedra formed by bismuth trifluoride in the glass are not involved in the medium-range order. In rare-earth-containing glasses, strong photoluminescence was discovered in the range 530–560 nm with excitation by the Raman-masking 532-nm wavelength. Bismuth in the glass enhances the europium photoluminescence level in the glass of the InF3-BiF3-BaF2-PbF2-ZnF2-EuF3 system.

Glass crystallization in the MnNbOF5-BaF2-BiF3 system as probed by Raman spectroscopy

Crystallization of glass samples with compositions of 20MnNbOF5-40BaF2-40BiF3, 20MnNbOF5-30BaF2-50BiF3, and 30MnNbOF5-30BaF2-40BiF3 has been studied using Raman spectroscopy. The study of band formation kinetics in high-frequency and low-frequency regions of the Raman spectrum provided information about the crystallization of the materials. The processes involved in glass crystallization have been found to be strongly dependent on the glass composition and annealing schedule. For 20MnNbOF5-40BaF2-40BiF3 and 20MnNbOF5-30BaF2-50BiF3 glasses, crystallization is accompanied by liquation, whereas for 30MnNbOF5-30BaF2-40BiF3 glass, crystallization does not involve noticeable liquation effects and occurs in one step.

Bismuth-containing fluoride glasses

The example of bismuth-containing glasses based on InF3 and ZrF4 is used to consider the effect of bismuth on glass formation, properties, and structure and the appearance of broadband luminescence at low wavelengths in the IR spectra of fluorozirconate glasses.