# US 7,608,553 B2 · Transparent rare-earth oxide sintered body and manufacturing method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,553 B2 - Document ID: US7608553B2 - Status: Granted - Kind: B2 - Application number: 11/589,795 - Filed: 2006-10-31 - Published: 2007-05-10 - Granted: 2009-10-27 - Earliest claimed: 2005-10-31 - Assignees: Covalent Materials Corporation - Inventors: Mitsuhiro Fujita; Masaki Irie - Web page: https://patentgrep.com/patent/US7608553B2 ## CPC - C04B 35/505: based on yttrium oxide - C04B 35/50: based on rare-earth compounds {(non-oxide rare earth compounds C04B35/5156)} - C04B 35/62695: {Granulation or pelletising (devices for shaping artificial aggregates from ceramic mixtures B28B1/004)} - C04B 2235/3251: Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof - C04B 2235/5409: expressed by specific surface values - C04B 2235/5436: micrometer sized, i.e. from 1 to 100 micron - C04B 2235/604: Pressing at temperatures other than sintering temperatures - C04B 2235/656: characterised by specific heating conditions during heat treatment - C04B 2235/6567: Treatment time - C04B 2235/658: Atmosphere during thermal treatment - C04B 2235/6581: Total pressure below 1 atmosphere, e.g. vacuum - C04B 2235/6582: Hydrogen containing atmosphere - C04B 2235/72: Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics - C04B 2235/9653: Translucent or transparent ceramics other than alumina - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE ## Abstract The invention intends to obtain a transparent yttrium oxide sintered body of which in-line transmittance in a visible wavelength region of 400 to 800 nm at a thickness of 1 mm is 60% or more, without using aluminum that readily segregates in grain boundaries of yttrium oxide, without using special raw materials in which a silicon content is particularly reduced and without finely pulverizing raw materials. A transparent yttrium oxide sintered body that contains, with yttrium oxide as a main component, at least either one of tantalum or niobium or both thereof and has the in-line transmittance of 60% or more at a thickness of 1 mm in a visible wavelength region in the range of 400 to 800 nm. ## Claims ### Claim 1 A transparent yttrium oxide sintered body, comprising: yttrium oxide as a main component; and niobium in solid solution with the yttrium oxide; wherein in-line transmittance when a thickness thereof is 1 mm in a visible wavelength region in a range of 400 to 800 nm is 60% or more. ### Claim 2 (depends on 1) The transparent yttrium oxide sintered body according to claim 1, wherein the body further comprises tantalum in solid solution with the yttrium oxide. ### Claim 3 (depends on 2) The transparent yttrium oxide sintered body according to claim 2, wherein the body comprises tantalum in a range of 0.1 to 1.3 wt % in terms of metal. ### Claim 4 A manufacturing method of a transparent yttrium oxide sintered body, comprising: adding at least one of niobium and a niobium compound to a yttrium oxide powder to blend therewith; forming the blended material to a yttrium oxide molded body containing the niobium; and sintering the yttrium oxide molded body at 1700° C. or more and 2000° C. or less under a vacuum, hydrogen or rare gas atmosphere to form a transparent yttrium oxide sintered body comprising yttrium oxide as a main component and niobium in solid solution with the yttrium oxide, wherein in-line transmittance when a thickness of the yttrium oxide sintered body is 1 mm in a visible wavelength region in a range of 400 to 800 nm is 60% or more. ### Claim 5 (depends on 4) The manufacturing method of the transparent yttrium oxide sintered body according to claim 4, wherein in the adding step tantalum or tantalum compound is further added in a range of 0.2 to 1.5 wt % to yttrium oxide in terms of metal to form a transparent yttrium oxide sintered body further containing tantalum in solid solution with the yttrium oxide. ### Claim 6 (depends on 4) The manufacturing method of a transparent yttrium oxide sintered body according to claim 4, wherein the niobium or the niobium compound is added in a range of 0.1 to 1.0 wt % to yttrium oxide in terms of metal. ### Claim 7 (depends on 4) The manufacturing method of the transparent yttrium oxide sintered body according to claim 4, wherein a specific surface area of yttrium oxide powder is 5 m2/g or more and 50 m2/g or less and wherein in the adding step at least one of tantalum and a tantalum compound is further added in a range of 0.2 to 1.5 wt % in terms of metal to form a transparent yttrium oxide sintered body further containing tantalum in solid solution with the yttrium oxide. ### Claim 8 (depends on 4) The manufacturing method of a transparent yttrium oxide sintered body according to claim 4, wherein a specific surface area of yttrium oxide powder is 5 m2/g or more and 50 m2/g or less and at least one of niobium and a niobium compound is added in a range of 0.1 to 1.0 wt % in terms of metal. ### Claim 9 (depends on 3) The transparent yttrium oxide sintered body according to claim 3, wherein the tantalum is contained in a range of 0.1 to 0.3 wt % in terms of metal, and no striae is contained. ### Claim 10 A transparent yttrium oxide sintered body, comprising: yttrium oxide as a main component; and niobium; wherein the niobium is contained in a range of 0.05 to 0.2 wt % in terms of metal, wherein the in-line transmittance at a thickness of 1 mm in a visible wavelength region in a range of 400 to 800 nm is 60% or more and no striae is contained. ### Claim 11 (depends on 1) The transparent yttrium oxide sintered body according to claim 1, wherein the body comprises niobium in a range of 0.05 to 0.5 wt % in terms of metal. ### Claim 12 (depends on 11) The transparent yttrium oxide sintered body according to claim 11, wherein the body comprises niobium in a range of 0.05 to 0.2 wt % in terms of metal and the sintered body does not contain striae.