Abstract: A glass wafer is provided that is made of a copper ions containing phosphate or fluorophosphate glass. The glass wafer has a diameter greater than 15 centimeters and a thickness of less than 0.4 millimeters. The glass wafer has two plane-parallel surfaces at least one of which is polished.

Abstract: A glass wafer is provided that is made of a copper ions containing phosphate or fluorophosphate glass. The glass wafer has a diameter greater than 15 centimeters and a thickness of less than 0.4 millimeters. The glass wafer has two plane-parallel surfaces at least one of which is polished.

Abstract: The invention can relate to essentially lead-free optical glasses having a refractive index nd of from about 1.65 to about 1.87 and an Abbe number &ngr;d of from about 27 to about 43 and a composition (in % by weight, based on oxide) of SiO2 about 10-about 25, B2O3>about 10-about 25, Na2O about 2.5-about 10, K2O 0-about 3, CaO about 0.5-about 5, BaO about 15-about 30, ZnO about 5-about 15, TiO2 about 6-about 15, ZrO2 about 0.5-about 8, Y2O3 about 0.1-about 2, La2O3 about 0.5-about 8, Nb2O5 about 6-about 12, with La2O3+Nb2O5≦about 17,Ta2O5 0-about 1, and Gd2O3 0-about 1.

Abstract: Substantially spherical particles of lithium silicates with improved mechanical properties and improved surface quality are provided, which are particularly suited for use as breeding material for tritium. The particles are characterised in that they contain additions of tellurium and/or tellurium compounds.

Abstract: Disclosed is a barium-free glass of good x-ray absorption, which has a composition (in wt.-% on the oxide basis) of SiO.sub.2 50-75; ZrO.sub.2 5-30; Li.sub.2 O 0-5; Na.sub.2 O 0-25; K.sub.2 O 0-25; .SIGMA. alkali oxides 0-25. Preferred is a dental glass of the composition of SiO.sub.2 55-70; ZrO.sub.2 10-25; Li.sub.2 O 0-15; Na.sub.2 O 10-25; K.sub.2 O 0-15; .SIGMA. alkaloids 15-25. The glass can furthermore contain also up to 3 wt.-% of fluorine, up to 5 wt.-% of MgO, up to 5 wt.-% of TiO.sub.2, and in each case up to 10 wt.-% of the oxides Al.sub.2 O.sub.3, GeO.sub.2, P.sub.2 O.sub.5, La.sub.2 O.sub.3, Y.sub.2 O.sub.3, Ta.sub.2 O.sub.3, Gd.sub.2 O.sub.3, ZnO and Nb.sub.2 O.sub.5. The glass finds its use in powder form with an average particle size of .ltoreq.10 .mu.m as filler for dental composites for filling teeth.

Abstract: Substantially spherical particles of lithium silicates with improved mechanical properties and improved surface quality are provided, which are particularly suited for use as breeding material for tritium. The particles are characterized in that they contain additions of tellurium and/or tellurium compounds.

Abstract: Lead- and barium-free crystal glass for the production of high-quality glasses and domestic articles, having high optical transmission, a refractive index n.sub.D of greater than 1.52, a density of at least 2.45 g/cm.sup.3, high hydrolytic resistance, good solarization resistance, and a K.sub.2 O+ZnO content of greater than 10% by weight, the glass system being based on an alkali-lime-silicate glass containing TiO.sub.2, ZrO.sub.2, Nb.sub.2 O.sub.3 and possibly Ta.sub.2 O.sub.5 and/or combinations thereof.

Abstract: A chemically resistant glass which can be produced at relatively low melting temperatures and has anomalous negative partial dispersion P.sub.g,F, a refractive index n.sub.d of from 1.73 to 1.83 and an Abbe coefficient v.sub.d of from 31 to 38 preferably contains (in % by weight, based on oxides):______________________________________ 0-4 SiO.sub.2 + GeO.sub.2 0-2 GeO.sub.2 0-10 MgO 26-33 B.sub.2 O.sub.3 0-1 Li.sub.2 O 0-16 CaO 19-50 PbO 0-1 Na.sub.2 O 0-16 BaO 1-6 ZrO.sub.2 0-1 K.sub.2 O 0-16 SrO 4-16 Ta.sub.2 O.sub.5 0-2 .SIGMA. alkaline earth 0-6 Al.sub.2 O.sub.3 metal oxides 0-16 ZnO 0-4 TiO.sub.2 1.5-20 .SIGMA. alkaline earth metal oxides + ZnO 0-1 WO.sub.3 0-11 La.sub.2 O.sub.3 0-7 Nb.sub.2 O.sub.5 0-5.5 Y.sub.2 O.sub.3 0-5.5 Gd.sub.2 O.sub.3 4-11 .SIGMA. La.sub.2 O.sub.3 + Y.sub.2 O.sub.3 + Gd.sub.2 O.sub.3 ______________________________________with the proviso that the .SIGMA.(SiO.sub.2 +GeO.sub.2 +B.sub.2 O.sub.3)/.SIGMA.(ta.sub.2 O.sub.5 +ZrO.sub.2 +HfO.sub.2) ratio is less than 5 and the PbO/.

Abstract: Silicate glasses are provided which when exposed to a silver ion exchange surface treatment are writable with electron beams. These glasses contain OD agents and do not require elements having 1-4 d-electrons in the atomic state.

Abstract: A glass having a negative anomalous partial dispersion .DELTA.P.sub.g,F, an index of refraction of n.sub.d .gtoreq.1.67 and an Abbe number of .nu..sub.d >36 has the following composition, in % by weight, 3-11 of SiO.sub.2, 0-3 of GeO.sub.2, .SIGMA. SiO.sub.2 +GeO.sub.2, 4.5-11; B.sub.2 O.sub.3, 29-35; 5-13 of Al.sub.2 O.sub.3 ; 1-3 of ZrO.sub.2 ; 0.2-3 of TiO.sub.2 ; 0.2-1.5 of Ta.sub.2 O.sub.5 ; 30-45 of PbO; 0-3 each of Li.sub.2 O, Na.sub.2 O, K.sub.2 O, Rb.sub.2 O, Cs.sub.2 O, .SIGMA. alkali metal oxide 0-3; 0-3.5 each of MgO, CaO, BaO, SrO, .SIGMA. alkaline-earth oxide 0-6, if .SIGMA. SiO.sub.2 and GeO.sub.2 .gtoreq.9; .SIGMA. alkaline-earth oxide 0-3.5, if .SIGMA. SiO.sub.2 and GeO.sub.2 <9; 0-14 of ZnO, 0-3 of La.sub.2 O.sub.3 ; 0-7 of Nb.sub.2 O.sub.3 ; 0-1 of Sb.sub.2 O.sub.3 ; 0-0.3 of As.sub.2 O.sub.3 ; 0-1.5 of WO.sub.3 ; 0-1 of F. This glass is inexpensive and can be produced in high quality, and has a high crystalization stability and good transmission values.