Abstract: A doped silica-titania glass article is provided that includes a glass article having a glass composition comprising (i) a silica-titania base glass, (ii) a fluorine dopant, and (iii) a second dopant. The fluorine dopant has a concentration of fluorine of up to 5 wt. % and the second dopant comprises one or more oxides selected from the group consisting of Al, Nb, Ta, B, Na, K, Mg, Ca and Li oxides at a total oxide concentration from 50 ppm to 6 wt. %. Further, the glass article has an expansivity slope of less than 0.5 ppb/K2 at 20° C. The second dopant can be optional. The composition of the glass article may also contain an OH concentration of less than 100 ppm.

Abstract: A method of forming a doped silica-titania glass is provided. The method includes blending batch materials comprising silica, titania, and at least one dopant. The method also includes heating the batch materials to form a glass melt. The method further includes consolidating the glass melt to form a glass article, and annealing the glass article.

Abstract: Ultralow expansion titania-silica glass. The glass has high hydroxyl content and optionally include one or more dopants. Representative optional dopants include boron, alkali elements, alkaline earth elements or metals such as Nb, Ta, Al, Mn, Sn Cu and Sn. The glass is prepared by a process that includes steam consolidation to increase the hydroxyl content. The high hydroxyl content or combination of dopant(s) and high hydroxyl content lowers the fictive temperature of the glass to provide a glass having a very low coefficient of thermal expansion (CTE), low fictive temperature (Tf), and low expansivity slope.

Abstract: A boron-doped titania-silica glass containing 0.1 wt % to 8.0 wt % boron, 9.0 wt % to 16.0 wt % TiO2, and 76.0 wt % to 90.9 wt % SiO2. The glass may further include F, Nb, Ta, Al, Li, Na, K, Ca, and Mg, individually or in combinations of two or more, at levels up to 4 wt %. The glass may have an OH concentration of more than 10 ppm. The glass features a CTE slope at 20° C. of less than 1 ppb/K2. The fictive temperature of the glass is less than 825° C. and the peak CTE of the glass is less than 30 ppb/K. The glass has two crossover temperatures and a wide temperature interval over which CTE is close to zero. The uniformity of each crossover temperature relative to its average over a volume of at least 50 cm3 is within ±5° C.

Abstract: A method for forming a Tzc gradient in a silica-titania glass article is provided. The method includes contacting a first surface of the glass article with a surface of a first heating module of a heating apparatus and contacting a second surface of the glass article with a surface of a second heating module of the heating apparatus. The method further includes raising the temperature of the first heating module to a first temperature, raising the temperature of the second heating module to a second temperature, and maintaining the first heating module at the first temperature and the second heating module at the second temperature for a predetermined period of time to form a thermal gradient through the glass article, the first temperature being greater than the second temperature. The method also includes cooling the glass article to form a Tzc gradient through the thickness of the glass article.

Abstract: A glass article for use in Extreme Ultra-Violet Lithography (EUVL) is provided. The glass article includes a silica-titania glass having a compositional gradient through the glass article, the compositional gradient being defined by the functions: [TiO2]=(c+f(x,y,z)), and [SiO2]=(100?{c+f(x,y,z)}??(x,y,z)) wherein [TiO2] is the concentration of titania in wt. %, [SiO2] is the concentration of silica in wt. %, c is the titania concentration in wt. % for a predetermined zero crossover temperature (Tzc), f(x, y, z) is a function in three-dimensional space that defines the difference in average composition of a volume element centered at the coordinates (x, y, z) with respect to c, and ?(x, y, z) is a function in three-dimensional space that defines the sum of all other components of a volume element centered at the coordinates (x, y, z).

Abstract: In one aspect the disclosure is directed to a binary silica-titania blank having a CTE of 0±30 ppb/° C. or less and a insert made of silica-titania-dopant(s) glass in the critical zone, wherein the dopants are selected from the group consisting of aluminum oxide, selected transition metal oxides, and amount of the dopants is in the range of 0.05 wt. % to 8 wt. % and the insert is fusion bonded to the blank with or without a frit. In various embodiments the dopants are selected from the group consisting of 0.25 wt. % to 8 wt. % Al2O3, 0.05 wt. % to 3 wt. % Nb2O5, and 0.25 wt. % to 6 wt. % Ta2O5.

Abstract: This disclosure is directed to a silica-titania-niobia glass and to a method for making the glass. The composition of the silica-titania-niobia (SiO2—TiO2—Nb2O5) glass, determined as the oxides, is Nb2O5 in an amount in the range of 0.005 wt. % to 1.2 wt. %, TiO2 in an amount in the range of 5 wt. % to 10 wt. %, and the remainder of glass is SiO2. In the method, the STN glass precursor is consolidated into a glass by heating to a temperature of 1600° C. to 1700° C. in flowing helium for 6 hours to 10 hours. When this temperature is reached, the helium flow can be replaced by argon for the remainder of the time. Subsequently the glass is cooled to approximately 1050° C., and then from 1050° C. to 700° C. followed by turning off the furnace and cooling the glass to room temperature at the natural cooling rate of the furnace.

Abstract: The present disclosure is directed to a doped silica-titania glass, DST glass, consisting essentially of 0.1 wt. % to 5 wt. % halogen, 50 ppm-wt. to 6 wt. % one or more oxides of Al, Ta and Nb, 3 wt. % to 10 wt. % TiO2 and the remainder SiO2. In an embodiment the halogen content can be in the range of 0.2 wt. % to 3 wt. % along with 50 ppm-wt. to 6 wt. % one or more oxides of Al, Ta and Nb, 3 wt. % to 10 wt. % TiO2 and the remainder SiO2. In an embodiment the DST glass has an OH concentration of less than 100 ppm. In another embodiment the OH concentration is less than 50 ppm. The DST glass has a fictive temperature Tf of less than 875° C. In an embodiment Tf is less than 825° C. In another embodiment Tf is less than 775° C.

Abstract: This disclosure is directed to a silica-titania-niobia glass and to a method for making the glass. The composition of the silica-titania-niobia (SiO2—TiO2—Nb2O5) glass, determined as the oxides, is Nb2O5 in an amount in the range of 0.005 wt. % to 1.2 wt. %, TiO2 in an amount in the range of 5 wt. % to 10 wt. %, and the remainder of glass is SiO2. In the method, the STN glass precursor is consolidated into a glass by heating to a temperature of 1600° C. to 1700° C. in flowing helium for 6 hours to 10 hours. When this temperature is reached, the helium flow can be replaced by argon for the remainder of the time. Subsequently the glass is cooled to approximately 1050° C., and then from 1050° C. to 700° C. followed by turning off the furnace and cooling the glass to room temperature at the natural cooling rate of the furnace.

Abstract: A method of drawing a glass clad wire is provided herein, the method comprising: (i) sealing off one end of a glass tube such that the tube has an open end and a closed end; (ii) introducing a wire material inside the glass tube; (iii) heating a portion of the glass tube such that the glass partially melts to form a first ampoule containing the wire material to be used in a drawing operation; (iv) introducing the first ampoule containing the wire material into a heating device; (v) increasing the temperature within the heating device such that the glass tube is heated enough for it to be drawn and wire material melts; and (vi) drawing the glass clad wire comprising a continuous wire of wire material, wherein the wire material is a metal, semi-metal, alloy, or semiconductor thermoelectrically active material, and wherein the wire diameter is equal to or smaller than about 5 ?m.

Abstract: In one aspect the disclosure is directed to a binary silica-titania blank having a CTE of 0±30 ppb/° C. or less and a insert made of silica-titania-dopant(s) glass in the critical zone, wherein the dopants are selected from the group consisting of aluminum oxide, selected transition metal oxides, and amount of the dopants is in the range of 0.05 wt. % to 8 wt. % and the insert is fusion bonded to the blank with or without a frit. In various embodiments the dopants are selected from the group consisting of 0.25 wt. % to 8 wt. % Al2O3, 0.05 wt. % to 3 wt. % Nb2O5, and 0.25 wt. % to 6 wt. % Ta2O5.

Abstract: In one aspect the disclosure is directed to a binary silica-titania glass blank having a CTE of 0±30 ppb/° C. or less over a temperature range of 5° C. to 35° C., and a doped silica-titania glass critical zone, wherein the dopant(s) are selected from the group consisting of aluminum oxide, and transition metal oxides, and amount of the dopant(s) is in the range of 0.05 wt. % to 8 wt. %. In various embodiments the dopants are selected from the group consisting of 0.25 wt. % to 8 wt. % Al2O3, 0.05 wt. % to 3 wt. % Nb2O5, and 0.25 wt. % to 6 wt. % Ta2O5, and mixtures thereof.

Abstract: A method of drawing a glass clad wire is provided herein, the method comprising: (i) sealing off one end of a glass tube such that the tube has an open end and a closed end; (ii) introducing a wire material inside the glass tube; (iii) heating a portion of the glass tube such that the glass partially melts to form a first ampoule containing the wire material to be used in a drawing operation; (iv) introducing the first ampoule containing the wire material into a heating device; (v) increasing the temperature within the heating device such that the glass tube is heated enough for it to be drawn and wire material melts; and (vi) drawing the glass clad wire comprising a continuous wire of wire material, wherein the wire material is a metal, semi-metal, alloy, or semiconductor thermoelectrically active material, and wherein the wire diameter is equal to or smaller than about 5 ?m.