A zone-optimized mirror (MZ) for reflecting extreme ultraviolet (EUV) or X-ray radiation (18) includes a reflective surface (S) having two or more substantially discrete zones (Z1, Z2, . . . Zn) that include respective coatings (C1, C2, . . . Cn). Each coating is configured to optimally reflect a select range of incident angles of the radiation incident thereon. An EUV optical system (10) and an EUV lithography system (200) that includes at least one zone-optimized mirror are also disclosed.

Provided is a zirconium oxide dispersion having a high concentration, a low viscosity, and high transparency, which exhibits a transmittance of 35% or above at a wavelength of 400nm, a transmittance of 95% or above at a wavelength of 800nm, and a viscosity of 20mPa·s or below at 25°C, and which has a content of zirconium oxide particles of 20wt% or higher. The zirconium oxide dispersion can be obtained by reacting a zirconium salt with an alkali in water to prepare a slurry of zirconium oxide particles; subjecting this slurry to filtration, washing, and repulping; adding an organic acid to the obtained slurry in an amount of one or more mols per mol of the zirconium contained in the slurry; subjecting the mixture thus obtained to hydrothermal treatment at a temperature of 170°C or higher to prepare an aqueous dispersion of zirconium oxide particles; washing the aqueous dispersion; and then concentrating the resulting aqueous dispersion.

The invention provides a dispersion of zirconium oxide having a content as high as 20% by weight or more, but a low viscosity, and having a high transparency, which has a transmittance of 35% or more at a wave length of 400 nm, a transmittance of 95% or more at a wave length of 800 nm, and a viscosity of 20 mPa·s or less at a temperature of 25°C. Such a dispersion of zirconium oxide can be obtained by reacting a zirconium salt with an alkali in water to obtain a slurry of particles of zirconium oxide; filtering, washing, and repulping the slurry; adding an organic acid to the resulting slurry in an amount of one mole part or more per mole part of the zirconium in the slurry; hydrothermally treating the slurry at a temperature of 170°C or higher; and washing and concentrating the resulting aqueous dispersion of particles of zirconium oxide.

Disclosed is a method for manufacturing an aqueous dispersion of zirconium oxide which has excellent transparency and for which fine zirconium oxide particles are uniformly dispersed in a dispersion medium, said method being characterized in that zirconium salt is reacted with an alkali in water to obtain a zirconium oxide particle slurry; next, this slurry is filtered, cleaned, and re-pulped, and at least one part by mole of an organic acid with respect to one part by mole of the zirconium in the slurry is added to the obtained slurry; and the obtained aqueous dispersion of zirconium oxide particles is cleaned after hydrothermal processing is performed at a temperature of 170°C or higher. Further disclosed is a method for manufacturing an aqueous dispersion of zirconium oxide which is a solid solution containing at least one type of stabilizing element selected from aluminum, magnesium, titanium, and rare earth elements.

The invention provides a process for producing an aqueous dispersion of zirconium oxide comprising: reacting a zirconium salt with an alkali in water to obtain a slurry of particles of zirconium oxide; filtering, washing, and repulping the slurry; adding an organic acid to the resulting slurry in an amount of one mole part or more per mole part of the zirconium in the slurry; hydrothermally treating the resulting mixture at a temperature of 170°C or higher; and washing the resulting aqueous dispersion of particles of zirconium oxide. The invention also provides a process for producing an aqueous dispersion of solid solution of zirconium oxide containing at least one stabilizing element selected from aluminum, magnesium, titanium, and rare earth elements. The invention further provides a process for producing a dispersion of zirconium oxide of which dispersion medium is an organic solvent, the process comprising replacing the dispersion medium of the aqueous dispersion of zirconium oxide obtained by the process mentioned above by the organic solvent.

The present invention relates to a translucent yttria-containing zirconia sintered body and a dental material, an orthodontic bracket and an artificial tooth, comprising said sintered body, as well as a mill blank for dental materials comprising said sintered body.

The invention relates to the use of a sintered body obtained by subjecting a primary sintered body having a relative density of 95% or higher produced from a fine yttria-containing zirconia powder to HIP sintering at a temperature of 1,200-1,600° C. and a pressure of 50 MPa or higher. This sintered body is either a sintered body which has a total light transmittance, as measured at a thickness of 0.5 mm, of 43% or higher and a three-point bending strength of 1,700 MPa or higher or a zirconia sintered body which has a total light transmittance, as measured at a thickness of 1 mm, of 40% or higher and a three-point bending strength of 500 MPa or higher and which combines high strength and total light transmission.

The present invention provides a metal oxide particle for a catalyst support comprising multiple species of metal oxides and capable of satisfactorily exerting the properties of the respective metal oxides, and also provide a production process therefor and an exhaust gas purifying catalyst obtained from this metal oxide particle. A metal oxide particle of the present invention comprises a core part 1 relatively rich in a first metal oxide and a surface layer 2 relatively rich in a second metal oxide, the core part and the surface layer each comprising a plurality of primary particles (1a, 2a), and the primary particle diameter of the second metal oxide being smaller than the primary particle diameter of the first metal oxide.

A process for producing zinc oxide fine particles comprising heating a mixture comprising a zinc source, a carboxyl-containing compound, and an alcohol; a process for producing zinc oxide-polymer composite particles, which comprises heating a mixture comprising a zinc source, a carboxyl-containing compound, a polymer, and an alcohol at a temperature of 100 DEG C or higher; a process for producing inorganic compound particles having on their surface a cluster of thin plate like zinc oxide crystals with their tip projecting outward, which comprises heating a mixture comprising a zinc source, a carboxyl-containing compound, lactic acid or a compound thereof, and an alcohol at a temperature of 100 DEG C or higher; a process for producing zinc oxide-based particles comprising heating a mixture comprising a zinc source, a carboxyl-containing compound, at least one element additive selected from the group consisting of the group IIIB metal elements and the group IVB metal elements, and an alcohol at a temperature of 100 DEG C or higher; zinc oxide-based fine particles obtained by these processes; and uses of the zinc oxide-based fine particles.