COMPOSITES OF THE SYSTEMS GERMANIUM – METAL OXIDE – BORON OXIDE AS PROSPECTIVE MATERIALS FOR INTERFERENCE OPTICS OF AN IR SPECTRUM RANGE

A fundamentally new type of materials – composites based on the Germanium- metal oxide systems – for applying interference coatings of IR spectral optics has been developed. The formation of a pair of volatile substances (one of them being Germanium monoxide), and their recombination is characteristic of compounds of Germanium and some p-metals (In, Ge, Sn), which have different volatilities in the lower and higher oxidation states. The introduction of a stabilizing additive B 2 O 3 to systems Ge – In 2 O 3 (-GeO 2 , -SnO 2 ) is proposed. It has been shown that between B 2 O 3 , which has acidic properties and In 2 O 3 , mainly of a basic nature, an interaction occurs that results in the formation of a complex oxide compound, Indium orthoborate of the InBO3 composition. This fact is confirmed by X-ray phase analysis and IR transmission spectroscopy. It has been established that B 2 O 3 addition not only affects the phase composition of the samples, but also the position of the In 2 O 3 vibrational bands. In turn, the presence of elemental Germanium in the system results in an increase in InBO3 content, the reason for which remains unclear. At the same time, the formation of ternary compounds in Ge – GeO 2 (SnO 2 ) – B 2 O 3 systems has not been established. Most likely, glass formation takes place in the first of the systems, while in the system with SnO2, immiscibility in the liquid phase and the formation of phases of unknown composition are visually observed. Partial systems GeO 2 (SnO 2 ) – B 2 O 3 during evaporation in vacuum destroy the material of the evaporator due to very high temperatures of the processes. On the contrary, the Ge- In 2 O 3 – B 2 O 3 system was successfully evaporated and a fairly strong coating was obtained. Presumably the interaction between Germanium, metal oxide and B 2 O 3 results in the formation of complex oxides such as borates of metals in various oxidation states, which stabilizes the evaporation process in vacuum and condensation of the coating with the necessary optical and operational properties.