The present invention provides a red light emitting glass ceramic and a preparation method thereof, and an LED/LD light emitting device. A.sub.2Al.sub.4Si.sub.5O.sub.18:Eu.sup.2+ cordierite of the red light emitting glass ceramic capable of realizing blue light excited red light emission is a crystal phase material, wherein A is at least one of Mg, Ca, Sr, Ba and Zn and at least comprises Mg. The present invention particularly provides the red light emitting glass ceramic taking a chemical formula A.sub.2Al.sub.4Si.sub.5O.sub.18:Eu.sup.2+ as a crystal phase. The present invention further provides a preparation method of the transparent glass ceramic. The glass ceramic comprising the crystal phase, with the chemical formula of Mg.sub.2Al.sub.4Si.sub.5O.sub.18:Eu.sup.2+, is excited by blue light to emit red light, the internal/external quantum efficiencies reaching up to 94.5%/70.6%, respectively.

The glass for covering a semiconductor element contains: in mol %, as a glass composition, SiO.sub.2: 20% to 36%, ZnO: 8% to 40%, B.sub.2O.sub.3: 10% to 24%, Al.sub.2O.sub.3: 10% to 20%, and MgO+CaO: 8% to 22%, in which SiO.sub.2/ZnO is 0.6 or more and less than 3.3 in terms of a molar ratio, and a lead component is substantially not contained.

The glass for covering a semiconductor element contains: in mol %, as a glass composition, SiO.sub.2: 20% to 36%, ZnO: 8% to 40%, B.sub.2O.sub.3: 10% to 24%, Al.sub.2O.sub.3: 10% to 20%, and MgO+CaO: 8% to 22%, in which SiO.sub.2/ZnO is 0.6 or more and less than 3.3 in terms of a molar ratio, and a lead component is substantially not contained.

A glass ceramic seal contains by weight, on an oxide basis 40-60% of SiO.sub.2, 25-28% of BaO, 10-20% of B.sub.2O.sub.3, 8-12% of Al.sub.2O.sub.3, 0-2% of ZrO.sub.2, 0-1% of Y.sub.2O.sub.3, 0-1% of CaO, and 0-1% of MgO.

A glass-ceramic article having greater than or equal to 65.00 wt. % and less than or equal to 80.00 wt. % SiO.sub.2, greater than 4.00 wt. % and less than or equal to 12.00 wt. % Al.sub.2O.sub.3, greater than or equal to 0.10 wt. % and less than or equal to 3.5 wt. % P.sub.2O.sub.5, greater than or equal to 8.00 wt. % and less than or equal to 17.00 wt. % Li.sub.2O, greater than or equal to 4.00 wt. % and less than or equal to 15.00 wt. % ZrO.sub.2, and greater than or equal to 0.05 wt. % and less than or equal to 4.00 wt. % CaO.

A glass ceramic article including a lithium disilicate crystalline phase, a petalite crystalline phased, and a residual glass phase. The glass ceramic article has a warp (μm)<(3.65×10.sup.−9/μm×diagonal.sup.2) where diagonal is a diagonal measurement of the glass ceramic article in μm, a stress of less than 30 nm of retardation per mm of glass ceramic article thickness, a haze (%)<0.0994t+0.12 where t is the thickness of the glass ceramic article in mm, and an optical transmission (%)>0.91×10.sup.(2−0.03t) of electromagnetic radiation wavelengths from 450 nm to 800 nm, where t is the thickness of the glass ceramic article in mm.

A glass-ceramic includes glass and crystalline phases, where the crystalline phase includes non-stoichiometric suboxides of titanium, forming ‘bronze’-type solid state defect structures in which vacancies are occupied with dopant cations.

The present invention relates to a glass in which: the glass is a crystallized glass; the glass has a difference log η−log η.sub.0 (dPa.Math.s) between a logarithm log η (dPa.Math.s) of bulk viscosity η (dPa.Math.s) and a logarithm log η.sub.0 (dPa.Math.s) of local viscosity η.sub.0 (dPa.Math.s) of larger than 0 and 1.8 or smaller, in a temperature range in which the logarithm log η.sub.0 (dPa.Math.s) of the bulk viscosity η (dPa.Math.s) is 11.4 or larger and 12.7 or smaller.

The present invention relates to a glass in which: the glass is a crystallized glass; the glass has a difference log η−log η.sub.0 (dPa.Math.s) between a logarithm log η (dPa.Math.s) of bulk viscosity η (dPa.Math.s) and a logarithm log η.sub.0 (dPa.Math.s) of local viscosity η.sub.0 (dPa.Math.s) of larger than 0 and 1.8 or smaller, in a temperature range in which the logarithm log η.sub.0 (dPa.Math.s) of the bulk viscosity η (dPa.Math.s) is 11.4 or larger and 12.7 or smaller.

Methods for engineered mesoporous cellular magmatics and articles thereof are disclosed. For example, the magmatics may include a mixture of substance that, when exposed to heat for a length of time, form a foamed mass. The foamed mass may be exposed to a solution configured to cause mineralization upon and within the articles.