MANUFACTURING PROCESS AND BOROPHOSPHATE GLASS PRODUCT CONTAINING LITHIUM OXIDE, ALUMINIUM OXIDE AND ZINC OXIDE, DOPED WITH RARE EARTHS AND TRANSITION AND POST-TRANSITION METALS, WITH MAGNETO-OPTICAL PROPERTIES

The invention relates to a borophosphate glass containing lithium oxide, aluminium oxide and zinc oxide, doped with rare earths, transitional and post-transitional metals and to a process for manufacturing the same, the glass being meant to be used for making Faraday rotators or magneto-optical sensors, as well as in other applications requiring materials with magneto-optical properties. According to the invention, the glass comprises network-forming elements, expressed as mole percentage: 5...20% BO, 14...75% PO, glass network modifiers: 2...15% LiO, chemical, thermal and mechanical stabilizers: 2...20% AlO, 2...20% ZnO, together with 3...75% of the following transitional and post-transitional metal oxides that induce magneto-optical properties, supplied as such or in pairs: CoO, FeO, FeO, FeO, VO, ZrO, NbO, MoO, WO, SnO, SbO, PbO, BiO, and rare earths oxides: TbO, DyO, CeO, EuO, PrO, NdO, SmO, GdO, HoO, ErO, TmOand YbO. The process, as claimed by the invention, has the following stages: wet preparation of raw material mixture while stirring continuously up to 120...150°C, after which it is poured, while still fluid, into the melting crucible, premelting of the said mixture at temperatures ranging between 150...900°C and controlled temperature growth up to the melting of the mixture, at temperatures of 950...1300°C, melt refining, homogenization and conditioning, pouring the glass melt into pure spectral graphite moulds preheated up to the annealing temperature, annealing in electric furnace with SiC wire resistors, followed by sample processing for determining their physical and chemical properties by cutting, grinding with Si carbide of 250, 400 and 600 mesh and polishing with cerium oxide suspensions with a grain size of 800 mesh.