Transparent ceramic and method for production thereof, and optical element

• Main Authors: KATSUBE MASAYOSHI, SUBE MITSURU, TANAKA NOBUHIKO, HIGUCHI YUKIO
• Format: Patent
• Language: English
• Published: 25.09.2003
• Edition: 7
• Subjects: ANTENNAS, i.e. RADIO AERIALS; ARTIFICIAL STONE; BASIC ELECTRIC ELEMENTS; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTRICITY; FREQUENCY-CHANGING; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; LIME, MAGNESIA; METALLURGY; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PERFORMING OPERATIONS; PHYSICS; REFRACTORIES; SLAG; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSPORTING; TREATMENT OF NATURAL STONE

A ceramic material powder for a translucent ceramic is molded with a binder, and the resulting green compact is embedded in a ceramic powder having the same composition with the ceramic material powder. After removing the binder, the green compact embedded in the ceramic powder is fired in an atmosphere having an oxygen concentration higher than that in the removal procedure of the binder and thereby yields a translucent ceramic represented by Formula I: Ba{(SnuZr1-u)xMgyTaz}vOw, Formula II: Ba(ZrxMgyTaz)vOw or Formula III: Ba{(SnuZr1-u)xZntMg1-t)yNbz}vOw. The translucent ceramic has a refractive index of 1.9 or more and is paraelectric.