| abstract |
TECHNICAL FIELD The present invention relates to the field of ceramics, and relates to a transparent spinel ceramic, or a method of manufacturing the same, which can be used, for example, as a protective ceramic. It is an object of the present invention to provide a transparent spinel ceramic with an in-line transmittance of more than 82% in the infrared wavelength range measured between 1000 nm and 2500 nm at a sample thickness of ≧ 3 mm and as free of visible defects as possible. will be. This object is achieved by a spinel ceramic which is transparent in the infrared wavelength range, which is respectively composed of 0.005 to <0.2 mass% of CaO and / or 0.005 to <0.5 mass% of SrO and / or 0.005 to <0.5 mass% of BaO Homogeneously distributed additives of calcium and / or strontium and / or barium, each present in concentrations expressed as oxides, with a maximum total amount of 0.5% by mass and with an average tissue particle size of ≦ 10 μm It is composed. |