Provided is a glass material that can satisfy both high Faraday effect and high light transmittance at wavelengths used. A glass material containing, in terms of % by mole of oxide, more than 40% Tb.sub.2O.sub.3 and having a percentage of Tb.sup.3+ of 55% by mole or more relative to a total content of Tb.

Provided is a glass material that can satisfy both high Faraday effect and high light transmittance at wavelengths used. A glass material containing, in terms of % by mole of oxide, more than 40% Tb.sub.2O.sub.3 and having a percentage of Tb.sup.3+ of 55% by mole or more relative to a total content of Tb.

Provided is a method that can manufacture a glass material having excellent homogeneity by containerless levitation. A block (12) of glass raw material is heated and melted by irradiation with a plurality of laser beams with the block (12) of glass raw material held levitated, thus obtaining a molten glass, and the molten glass is then cooled to obtain a glass material. The plurality of laser beams include a first laser beam (13A) and a second laser beam (13B). A size () of an angle formed between the first laser beam (13A) and the second laser beam (13B) is 0 or more but less than 180. A center (C1) of a spot (S1) of the first laser beam (13A) on the surface of the block (12) of glass raw material and a center (C2) of a spot (S2) of the second laser beam (13B) on the surface of the block 12 of glass raw material are different from each other.

Provided is a method that can manufacture a glass material having excellent homogeneity by containerless levitation. A block (12) of glass raw material is heated and melted by irradiation with a plurality of laser beams with the block (12) of glass raw material held levitated, thus obtaining a molten glass, and the molten glass is then cooled to obtain a glass material. The plurality of laser beams include a first laser beam (13A) and a second laser beam (13B). A size () of an angle formed between the first laser beam (13A) and the second laser beam (13B) is 0 or more but less than 180. A center (C1) of a spot (S1) of the first laser beam (13A) on the surface of the block (12) of glass raw material and a center (C2) of a spot (S2) of the second laser beam (13B) on the surface of the block 12 of glass raw material are different from each other.

A substrate for an EUV mirror which contains a zero crossing temperature profile that departs from the statistical distribution is provided. A method for producing a substrate for an EUV mirror is also provided, in which the zero crossing temperature profile in the substrate is adapted to the operating temperature of the mirror. A lithography method using the substrate is also described.

A substrate for an EUV mirror which contains a zero crossing temperature profile that departs from the statistical distribution is provided. A method for producing a substrate for an EUV mirror is also provided, in which the zero crossing temperature profile in the substrate is adapted to the operating temperature of the mirror. A lithography method using the substrate is also described.

According to one embodiment, a method for thermally treating glass articles may include holding a glass article at a treatment temperature equal to an annealing temperature of the glass article 15 C. for a holding time greater than or equal to 5 minutes. Thereafter, the glass article may be cooled from the treatment temperature through a strain point of the glass article at a first cooling rate CR1 less than 0 C./min and greater than 20 C./min such that a density of the glass article is greater than or equal to 0.003 g/cc after cooling. The glass article is subsequently cooled from below the strain point at a second cooling rate CR.sub.2, wherein |CR.sub.2|>|CR.sub.1|.

According to one embodiment, a method for thermally treating glass articles may include holding a glass article at a treatment temperature equal to an annealing temperature of the glass article 15 C. for a holding time greater than or equal to 5 minutes. Thereafter, the glass article may be cooled from the treatment temperature through a strain point of the glass article at a first cooling rate CR1 less than 0 C./min and greater than 20 C./min such that a density of the glass article is greater than or equal to 0.003 g/cc after cooling. The glass article is subsequently cooled from below the strain point at a second cooling rate CR.sub.2, wherein |CR.sub.2|>|CR.sub.1|.

[Object] To provide a means manufacturing a medical vial which contains a Type IA borosilicate glass as the raw material and in which the elution amount of silica into a high ionic strength solution decreases to be equal to or less than the silica elution amount in a Type IB borosilicate glass. [Solution] A method for manufacturing a medical vial is a method for manufacturing a medical vial including a fire blast process of applying a flame ejected from a point burner to a deteriorated layer generated on the inner surface of a vial, in which the vial is molded from a glass tube containing a Type IA borosilicate glass as the raw material and the molar ratio of oxides contained in the borosilicate glass satisfies =0.230.02 in =[(Na.sub.2O+K.sub.2O)Al.sub.2O.sub.3]/B.sub.2O.sub.3 and satisfies =7.50.5 in =B.sub.2O.sub.3/Al.sub.2O.sub.3.

[Object] To provide a means manufacturing a medical vial which contains a Type IA borosilicate glass as the raw material and in which the elution amount of silica into a high ionic strength solution decreases to be equal to or less than the silica elution amount in a Type IB borosilicate glass. [Solution] A method for manufacturing a medical vial is a method for manufacturing a medical vial including a fire blast process of applying a flame ejected from a point burner to a deteriorated layer generated on the inner surface of a vial, in which the vial is molded from a glass tube containing a Type IA borosilicate glass as the raw material and the molar ratio of oxides contained in the borosilicate glass satisfies =0.230.02 in =[(Na.sub.2O+K.sub.2O)Al.sub.2O.sub.3]/B.sub.2O.sub.3 and satisfies =7.50.5 in =B.sub.2O.sub.3/Al.sub.2O.sub.3.