Schott Ag

Schott Glas

Dirk Sprenger

Thilo Zachau

Friedrich Siebers

Rainer Liebald

Bernd Hoppe

Martin Letz

Karine Seneschal-Merz

Jochen Alkemper

Holger Wegener

Peter Brix

Edgar Pawlowski

Bianca Schreder

Burkhard Speit

Joerg Hinrich Fechner

Meike Schneider

Heinrich Ostendarp

Dietrich Mund

Ulrich Fotheringham

Wolfram Beier

Jose Zimmer

Juergen Leib

Hans-Werner Beudt

Eva Hoelzel

Horst Loch

Markus Schweizer

Rudolf Mueller

Meike Lohmann

Wolfgang Buergel

The invention provides a method for producing a glass ceramic comprising the steps of melting a starting glass that is free from alkali, except for incidental contamination, and that contains at least one garnet-forming agent and at least one oxide of a lanthanoid; grinding the starting glass to produce a glass frit; molding by pressing and sintering the glass frit until at least one garnet phase containing lanthanoids is formed. A glass ceramic produced in this way may contain 5-50% by weight of SiO, 5-50% by weight of AlOand 10-80% by weight of at least one oxide selected from the group formed by YO, LuO, ScO, GdO, YbO, CeO, as well as 0.1-30% by weight of at least one oxide selected from the group formed by BO, ThO, and oxides of the lanthanoids, except LuO, GdO, YbO, CeO. Such a glass ceramic is suited especially for down conversion of excitation radiation in the blue and in the UV region of the spectrum.

Sintered glass ceramic and method for producing the same

The invention proposes a method for producing glass ceramics which is particularly well suited as light conversion material, especially for down conversion. One initially produces a starting glass, containing (on an oxide basis) 5-50% by weight of SiO, 5-50% by weight of AlOand 10-80% by weight of at least one oxide selected from the from the group formed by YO, LuO, ScO, GdO, YbO, CeO, as well as 0.1-30% by weight of at least one oxide selected from the group formed by BO, ThO, and oxides of the lanthanoids, except LuO, GdO, YbO, CeO. Thereafter, the material is heated up for ceramization at a heating rate of at least 100 K/min to a temperature in the range of between 1000&#xb0; C. to 1400&#xb0; C. until crystallites are formed that contain a garnet phase. Thereafter, the material is cooled down to room temperature. Alternatively, controlled cooling-down from the molten state is possible.

Method for producing a glass ceramic having a garnet phase

The invention provides a method for producing a glass ceramic comprising the steps of melting a starting glass that is free from alkali, except for incidental contamination, and that contains at least one garnet-forming agent and at least one oxide of a lanthanoid; grinding the starting glass to produce a glass frit; molding by pressing and sintering the glass frit until at least one garnet phase containing lanthanoids is formed. A glass ceramic produced in this way may contain 5-50 % by weight of SiO, 5-50 % by weight of AlOand 10-80 % by weight of at least one oxide selected from the group formed by YO, LuO, ScO, GdO, YbO, CeO, as well as 0.1-30% by weight of at least one oxide selected from the group formed by BO, ThO, and oxides of the lanthanoids, except LuO, GdO, YbO, CeO. Such a glass ceramic is suited especially for down conversion of excitation radiation in the blue and in the UV region of the spectrum.

The invention relates to a glass ceramic armour material consisting (in % by weight in relation to oxide base) of 5-33 SiO, 20-50 AlO, 5-40 MgO, 0-15 BO, 0.1-30 YO, LnO, AsO, NbOand/or ScOand 0-10 PO. The inventive armour material can also be reinforced with inorganic reinforcing fibres in a quantity of 5-65% by weight, preferably consisting of C, SiC, SiN, AlO, ZrOor Sialon. Said armour material is characterised in that it exhibits a high elasticity modulus and is producible from green glass without to fear a premature crystallisation.

Armor material made of glass ceramics

The method of making thin glass panes includes conveying a glass melt through a vertical inlet to a drawing tank with a slit nozzle; drawing a glass ribbon downward from the slit nozzle; setting a total throughput by setting length and cross section of the inlet and by heating and cooling the inlet to control glass melt viscosity so that pressure in the inlet decreases; and setting a throughput per unit of length in a lateral direction along the glass ribbon via nozzle system geometry and by heating and cooling of the drawing tank and slit nozzle to control melt viscosity, so that glass does not wet an underside of the slit nozzle near a breaking edge. The setting of the total throughput and the throughput per unit length are largely decoupled to simplify process control. An inventive apparatus for performing the method is also disclosed.

Method and device for producing thin glass panes

A glass ceramic is specified, with a crystalline phase consisting predominantly of BPO, and preferably exclusively of BPO. The glass ceramic contains 10 to 50 wt.-% SiO, 5 to 40 BO, 25 to 75 wt.-% PO, up to 5 wt.-% refining agents, up to 1 wt.-% impurities, and 0.1 to 10 wt.-% of at least one constituent selected from the group of M3O, M5Oand M4O, wherein M3 is an element selected from the group of the lanthanoids, yttrium, iron, aluminum, gallium, indium and thallium; wherein M5 is an element selected from the group of vanadium, niobium and tantalum and wherein M4 is an element selected from the group of titanium, zirconium, hafnium and cerium. The glass ceramic is advantageously suitable for being coated with semiconductor materials.

Glass ceramic

In the method for microstructuring flat glass substrates a substrate surface of a glass substrate is coated with at least one structured mask layer and subsequently exposed to a chemically reactive ion etching process (RIE) with at least one chemical etching gas. In order to provide the same or a higher quality etching and etching rate even for economical types of glass the chemical etching gas is mixed with at least one noble gas, so that the proportion of sputtering etching in the ion etching process is significantly increased.

Method for microstructuring flat glass substrates

An aluminoborosilicate glass having a density less than 2.40 g/cmand a specific modulus of elasticity greater than 30 GPa&#xb7;cm&#xb7;gis disclosed that comprises the following components (in wt. %): SiO58-70, AlO12-20, BO5-15, MgO 0-9, CaO 2-12, BaO 0, 1-5, SnO0-1, AsO0-2, the glass, apart from random impurities, being free of SrO and free of alkali oxides. The glass is particularly suitable as a substrate glass for LCD displays, for example.

Aluminoborosilicate glass

A glass ceramic comprises (in wt.-% on oxide basis): SiO35 to 60, BO&#x3e;4 to 10, PO0 to 10, AlO16.5 to 40, TiO1 to 10, TaO0 to 8, YO0 to 6, ZrO1 to 10, MgO 6 to 20, CaO 0 to 10, SrO 0 to 4, BaO 0 to 8, ZnO 0 to 4, SnO+CeO0 to 4, SO+Cl0 to 4, wherein the total content (SnO+CeO+SO+Cl) is between 0.01 and 4 wt.-%. The glass ceramic may be processed by the float glass method, may be transparent and is, inter alia, suitable as a substrate for thin film semiconductors, in particular for display applications, solar cells etc.

Glass ceramic and method of producing the same

The invention relates to crystallizable aluminosilicate magnesium-containing glass which is used for producing extremely solid and break-resistant glass-ceramics having an easily polished surface. The inventive crystallizable glass contains 5-33 mass % of SiO, 25-40 mass % of AlO, 5-25 mass % of MgO, 0-15 mass % of BO, 0.1-30 mass % of YO, LnO, AsOand/or NbOand 0.1-10 mass % of PO.

Crystallizable glass and the use thereof for producing extremely solid and break resistant glass-ceramics having an easily polished surface

A method is described for making low-stress single crystals with a hexagonal crystal structure, which has a crystallographic c-axis perpendicular to a [0001] surface. A single crystal maintained at a temperature under the melting point of the crystal raw material is dipped in a melt of the crystal raw material, whereby a solid-liquid phase boundary is formed. The crystal is subsequently drawn with an upwardly directed drawing motion e.g. by the Czochralski method. The method is characterized by drawing the crystal along the c-axis so that a temperature gradient of at least 30 K/cm is present in the crystal within a centimeter of the solid-liquid phase boundary and by subsequently performing a tempering treatment on the resulting single crystal. The method is especially suitable for corundum crystals, such as sapphire, which are used as substrates for semiconductor components, such as LEDs.

Method of growing hexagonal single crystals and use of same as substrates for semiconductor elements

A simple and economical method is described for compacting or shrinking flat glass panes. The method ensures high temperature homogeneity in the glass. First, the glass panes are cleaned and then a stack of glass panes to be treated is assembled without applying a release agent to any of the glass panes. Then the stack of glass panes is placed between ceramic panels made of silicon-infiltrated silicon carbide and this stack together with the ceramic panels is subjected to a heat treatment in a radiation furnace at temperatures ranging from 300&deg; C. to 900&deg; C. The ceramic panels have a thermal conductivity, which, in the region of the heat treatment temperature, is at least 5 times as large as that of the glass panes. The ratio of the total thickness of the ceramic panels to the height of the glass stack should be at least 1/&lgr;/40W/(mK), wherein &lgr; is the thermal conductivity of the ceramic panel at the temperatures of the heat treatment.

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Stadecken-Elsheim, Germany

Dirk Sprenger