Abstract: A sputtering target for forming a ZrO2—In2O3 based protective film for an optical storage medium, has a component composition made of ZraInbAcO100-a-b-c where “A” represents one, two, or more of Si, Cr, Al, Ce, Ti, and Sn, “a” represents an amount greater than 5 atomic percent and less than 23 atomic percent, “b” represents an amount greater than 12 atomic percent and less than 35 atomic percent, and “c” represents an amount greater than 0 and less than 30 atomic percent, wherein 90% or more of Zr that is included in the sputtering target for forming the protective film for the optical storage medium is in an oxidative product phase in which Zr and In are combined, and is dispersed in a base material of the target.

Abstract: A powder including, in percentages by weight: (a) 94% to 99% of particles of at least one refractory material, the main constituent(s) of which are alumina and/or zirconia and/or silica; (b) 1% to 6% of a hydraulic cement; (c) 0 to 0.03% of organic fibers; (d) optionally, 0.075% to 1% of a surfactant; and (e) optionally, a setting accelerator, where the fraction of particles having a size below 40 ?m being distributed, in percentages by weight relative to the weight of the powder, in the following manner: (1) fraction<0.5 ?m: ?4%, (2) fraction<2 ?m: ?5%, fraction<10 ?m: ?16%, and fraction<40 ?m: 29-45%, where the proportion of zirconia in the fraction of particles having a size smaller than 10 ?m, called “fines”, is between 35% and 75% by weight relative to the total weight of said fraction.

Abstract: Disclosed are ceramic articles comprising ceramic honeycomb bodies and an aqueous composition, for example in the form of a cold-set plug, as well as processes for preparing ceramic articles and processes for making an aqueous composition for use with ceramic articles, for example as a cold-set plug composition.

Abstract: A material for dentures having a 3-point bending strength of at least 1300 MPa, dentures produced from said type of material, corresponding blank materials, a method for producing blanks, and a method for producing a denture part made from said material or a blank.

Abstract: In one aspect, the invention includes a refractory material, said material comprising: (i) at least 20 wt. % of a first grain mode stabilized zirconia based upon the total weight of said material, said first grain mode having a D50 grain size in the range of from 5 to 2000 ?m, said stabilized zirconia including a matrix oxide stabilizer; (ii) at least 1 wt. % of a second grain mode having a D50 grain size in the range of from 0.01 ?m up to not greater than one-fourth the D50 grain size of said first grain mode zirconia, based upon the total weight of said material; and (iii) at least 1 wt. % of a preservative component within at least one of said first grain mode stabilized zirconia, said second grain mode stabilized zirconia, and an optional another grain mode; wherein after sintering, said material has porosity at 20° C. in the range of from 5 to 45 vol %.

Abstract: This invention relates to thermally sprayed coatings of a high purity yttria or ytterbia stabilized zirconia powder, said high purity yttria or ytterbia stabilized zirconia powder comprising from about 0 to about 0.15 weight percent impurity oxides, from about 0 to about 2 weight percent hafnium oxide (hafnia), from about 6 to about 25 weight percent yttrium oxide (yttria) or from about 10 to about 36 weight percent ytterbium oxide (ytterbia), and the balance zirconium oxide (zirconia). Thermal barrier coatings for protecting a component such as blades, vanes and seal surfaces of gas turbine engines, made from the high purity yttria or ytterbia stabilized zirconia powders, have a density greater than 88% of the theoretical density with a plurality of vertical macrocracks homogeneously dispersed throughout the coating to improve its thermal fatigue resistance.

Abstract: The present invention resides in a refractory composition for use as a cold start slag band. The composition comprises an admixture of partially stabilised zirconia and/or fully stabilised zirconia and monoclinic zirconia, characterised in that the proportion of monoclinic relative to the total zirconia content is at least 40% by weight. The invention also resides in a slag band formed from the composition, a submerged entry nozzle incorporating the slag band and a method of forming such a submerged entry nozzle.

Abstract: A powder including: (a) more than 92% of zircon particles; (b) 1% to 2% of silica particles having a size less than 50 microns; (c) 0.3% to 5% of particles comprising one, two, or three oxides selected from CaO, MgO, and Y2O3; (d) less than 1% of particles comprising other oxides; the powder also being such that it includes: more than 5% of zircon aggregate particles having a size greater than 1 mm; and 8% to 20% of zircon matrix particles having a size less than 15 ?m and including, for more than 95% of the weight thereof, a monoclinic phase.

Abstract: Specialty ceramic materials which resist corrosion/erosion under semiconductor processing conditions which employ a corrosive/erosive plasma. The corrosive plasma may be a halogen-containing plasma. The specialty ceramic materials have been modified to provide a controlled electrical resistivity which suppresses plasma arcing potential.

Abstract: An object of the present invention is to provide a catalyst exhibiting excellent performance particularly in partial oxidation reaction. Another object is to provide a method for efficiently producing carboxylic acid or carboxylic anhydride through vapor-phase partial oxidation of an organic compound by use of an oxygen-containing gas in the presence of the catalyst. The catalyst contains (1) diamond; (2) at least one species selected from among Group 5 transition element oxides, collectively called oxide A; and (3) at least one species selected from among Group 4 transition element oxides, collectively called oxide B. The method for producing a carboxylic acid or a carboxylic anhydride includes subjecting an organic compound to vapor phase partial oxidation by use of an oxygen-containing gas in the presence of the catalyst, wherein the organic compound is an aromatic compound having one or more substituents in a molecule thereof, the substituents each including a carbon atom bonded to an aromatic ring.

Abstract: The invention relates to primary particles of oxide-ceramic material, wherein the primary particles have an average particle size in the range from 10 to 1000 nm and are coated with a chromophoric component, a process for their preparation and their use in particular in the preparation of ceramic moldings and dental restorations. The invention further relates to a suspension based on oxide-ceramic material which contains the primary particles, and a process for the preparation of a ceramic moldings.

Abstract: The invention relates to a sintered product containing: in mass percent based on oxides, more than 99.5% of a material having a cubic crystallographic structure for more than 95% of the mass thereof, known as a material with a cubic structure, and having a refractive index of less than 2.75 in the wavelength range between 0.2 ?m and 5 ?m; and more than 50 ppma of dopants which must contain titanium oxide TiO2 and at least one additional dopant selected from ZrO2, CaO, and MgO, in which said at least one additional dopant is different from the oxide(s) forming the material with a cubic structure, but can be MgO when the material with a cubic structure is spinel MgAl2O4.

Abstract: A translucent zirconia sintered body, a dental article comprising a shaped, translucent zirconia body, a zirconia green body, and methods of making a translucent zirconia sintered body, methods of making a dental article comprising a shaped, translucent zirconia body, and methods of making a zirconia green body are described.

Abstract: Unlike conventional dental ceramic powder made by grinding, dental ceramic nanocrystals are formed by vaporization into individual particles. Tetragonal zirconia particles thus formed are not broken into pieces, and so do not transform to weaker monoclinic zirconia and weaker sintered products. The particles created by this approach can be much smaller, and dental prostheses sintered from this powder can be stronger and more realistic. For instance, the smaller size of sintered tetragonal zirconia crystals increases optical translucence by reducing scattering from birefringence, and the small average particle size and tight distribution of sizes and shapes can essentially eliminate pores in a sintered product. Cylindrical and spherical particles can be manufactured by this approach, whereas prior art dental ceramic particles were generally neither.

Abstract: In one aspect, the invention includes a heat stable, formed ceramic component that includes a multimodal grain distribution including (i) at least 50 wt % of coarse grains including stabilized zirconia, the coarse grains comprising a D50 grain size in the range of from 5 to 800 ?m, based upon the total weight of the component; and (ii) at least 1 wt % of fine grains comprising a D50 average grain size not greater than one-fourth the D50 grain size of the coarse grain, dispersed within the coarse grains, based upon the total weight of the component; wherein after sintering, the component has porosity at ambient temperature in the range of from 5 to 45 vol. %, based on the formed volume of the component.

Abstract: A refractory object can include at least 10 wt % Al2O3. In an embodiment, the refractory object can further include a dopant including an oxide of a rare earth element, Ta, Nb, Hf, or any combination thereof. In another embodiment, the refractory object may have a property such that the averaged grain size does not increase more than 500% during sintering, an aspect ratio less than approximately 4.0, a creep rate less than approximately 1.0×10?5 ?m/(?m×hr), or any combination thereof. In a particular embodiment, the refractory object can be in the form of a refractory block or a glass overflow forming block. The glass overflow forming block can be useful in forming an Al—Si—Mg glass sheet. In a particular embodiment, a layer including Mg—Al oxide can initially form along exposed surfaces of the glass overflow forming block when forming the Al—Si—Mg glass sheet.

Abstract: Methods of making and compositions of dense sintered ceramic nano- and micro-composite materials that are highly stable in a variety of conditions and exhibit superior toughness and strength. Liquid feed flame spray pyrolysis techniques form a plurality of nanoparticles (e.g., powder), each having a core region including a first metal oxide composition comprising Ce and/or Zr or other metals and a shell region including a second metal oxide composition comprising Al or other metals. In certain aspects, the core region comprises a partially stabilized tetragonal ZrO2 and the shell region comprises an ?-Al2O3 phase. The average actual density of the ceramic after sintering is greater than 50% and up to or exceeding 90% of a theoretical density of the ceramic.

Abstract: A low temperature co-fired ceramic material includes a SiO2—BaO—Al2O3-based primary component, and, as secondary components, 0.044 to 0.077 parts by weight of iron in terms of Fe2O3 and 0.30 to 0.55 parts by weight of zirconium in terms of ZrO2 relative to 100 parts by weight of the SiO2—BaO—Al2O3-based primary component. The SiO2—BaO—Al2O3-based primary component preferably includes 47% to 60% by weight of SiO2, 20% to 42% by weight of BaO, and 5% to 30% by weight of Al2O3.

Abstract: The present invention provides biocidal ceramic compositions incorporating a bioactive ionic species that is chemically bound in a substantially single-phase, crystalline, [NZP]-type structure, methods for producing the crystalline structures, and articles of manufacture incorporating the crystalline structures, and uses of the articles of manufacture. Bioactive ionic species can be, but are not limited to, Ag, Cu, Ni, Zn, Mn, Sn, Co, H, and combinations thereof.

Abstract: This invention relates to thermal spray composite coatings on a metal or non-metal substrate. The thermal spray composite coatings comprise a ceramic composite coating having at least two ceramic material phases randomly and uniformly dispersed and/or spatially oriented throughout the ceramic composite coating. At least a first ceramic material phase is present in an amount sufficient to provide corrosion resistance to the ceramic composite coating, and at least a second ceramic material phase is present in an amount sufficient to provide plasma erosion resistance to the ceramic composite coating. This invention also relates to methods of protecting metal and non-metal substrates by applying the thermal spray coatings. The composite coatings provide erosion and corrosion resistance at processing temperatures higher than conventional processing temperatures used in the semiconductor etch industry, e.g., greater than 100° C.

Abstract: The present invention provides a high-purity fused and crushed stabilized zirconia powder. The powder—with or without further processing, such as plasma spheroidization—is used in thermal spray applications of thermal barrier coatings (TBCs) and high-temperature abradables. The resulting coatings have a significantly improved high temperature sintering resistance, which will enhance the durability and thermal insulation effect of the coating.

Abstract: This invention relates to high purity yttria or ytterbia stabilized zirconia powders comprising from about 0 to about 0.15 weight percent impurity oxides, from about 0 to about 2 weight percent hafnium oxide (hafnia), from about 6 to about 25 weight percent yttrium oxide (yttria) or from about 10 to about 36 weight percent ytterbium oxide (ytterbia), and the balance zirconium oxide (zirconia). Thermal barrier coatings for protecting a component such as blades, vanes and seal surfaces of gas turbine engines, made from the high purity yttria or ytterbia stabilized zirconia powders, have a density greater than 88% of the theoretical density with a plurality of vertical macrocracks homogeneously dispersed throughout the coating to improve its thermal fatigue resistance.

Abstract: A gasifier comprising an interior wall on which a layer is applied or an interior wall protected by an assembly of blocks, said layer or said blocks having at least one region of a sintered material containing: i) at least 25% by weight of chromium oxide Cr2O3; and ii) at least 1% by weight of zirconium oxide, wherein at least 20% by weight of said zirconium oxide ZrO2 is stabilized in the cubic and/or quadratic form.

Abstract: The invention relates to compositions based on Ce-stabilized ZrO2, and single- and multi-colored blanks made from oxide ceramics, and a process for their preparation, in which oxide ceramic powder is coated with a coloring substance, the coated powders are preferably graded and at least one colored powder is filled into a compression mould, the colored powder or powders are compressed to produce a shaped body, and the compressed shaped body is sintered to produce a blank, and to the use of these blanks for the preparation of dental restorations. The compositions exhibit high fracture toughness and high flexural strength.

Abstract: The invention relates to a molten ceramic particle, characterized in that it has the following chemical composition in wt % based on oxides and for a total of 100%: 55%<ZrO2+HfO2<70%; 20%<SiO2<30%; 6.5%<MgO<9.5%; Al2O3 in an amount such that the mass ratio MgO/Al2O3 is comprised between 2.4 and 6.6; and less than 0.6% of other oxides.

Abstract: Slip for use in a hot-melt inkjet printing process which contains (A) ceramic particles, (B) wax and (C) at least one radically polymerizable monomer, and use of the slip to prepare dental restorations. Furthermore, a process for the preparation of a green compact is described, in which the slip is molded in layers to the geometrical shape of the green compact and subjected to a radical polymerization in order to obtain a cured green compact.

Abstract: The present invention provides a fused cast refractory block comprising a mean zirconia (ZrO2+HfO2) content of more than 85% as a percentage by weight based on the oxides, and with a standard deviation ? of the local zirconia content divided by the volume of the block of less than 7.5.

Abstract: There is described a ceramic powder, ceramic layer and layer system having gadolinium/mixed crystal pyrochlore phases and oxides. Besides a good thermal insulation property, thermal insulation layer systems must also have a long lifetime of the thermal insulation layer. The layer system according to the invention has an outer ceramic layer, which comprises a mixed crystal of gadolinium zirconate and gadolinium hafnate.

Abstract: A ceramic article useful in semiconductor processing, which is resistant to erosion by halogen-containing plasmas. The ceramic article is formed from a combination of yttrium oxide and zirconium oxide. In a first embodiment, the ceramic article includes ceramic which is formed from yttrium oxide at a molar concentration ranging from about 90 mole % to about 70 mole %, and zirconium oxide at a molar concentration ranging from about 10 mole % to about 30 mole %. In a second embodiment, the ceramic article includes ceramic which is formed from zirconium oxide at a molar concentration ranging from about 96 mole % to about 94 mole %, and yttrium oxide at a molar concentration ranging from about 4 mole % to about 6 mole %.

Abstract: A powder including: (a) more than 92% of zircon particles, (b) 1% to 2% of silica particles having a size less than 50 microns; (c) 0.3% to 5% of particles comprising one, two, or three oxides selected from CaO, MgO, and Y2O3; (d) less than 1% of particles comprising other oxides; the powder also being such that it includes: more than 5% of zircon aggregate particles having a size greater than 1 mm; and 8% to 20% of zircon matrix particles having a size less than 15 ?m and including, for more than 95% of the weight thereof, a monoclinic phase.

Abstract: There is described a Ceramic Powder, a Ceramic Layer and a Layer System with Pyrochlore Phase and Oxides. Besides a good thermal insulation property, thermal insulation layer systems must also have a long lifetime of the thermal insulation layer. A described layer system has a layer sequence of a metallic bonding layer, an inner ceramic layer and an outer ceramic layer, which are specially matched to one another.

Abstract: Method for producing a mold for use in casting reactive metals comprising preparing a slurry of a yttria-based refractory composition and a binder, and using said slurry as a mold facecoat by applying said slurry onto a surface of a mold pattern, wherein said yttria-based refractory composition is obtainable by (a) mixing particles of a yttria-based ceramic material and a fluorine containing dopant, and (b) heating the resulting mixture to effect fluorine-doping of said yttria-based ceramic material.

Abstract: Refractory materials are provided which contain P2O5/R2O3 constituents, where R is Y, Sc, Er, Lu, Yb, Tm, Ho, Dy, Tb, Gd, or a combination thereof, and/or V2O5/R?2O3 constituents where R? is Y, Sc, one or more rare earth elements, or a combination thereof. In certain embodiments, the refractory materials are xenotime-type materials and/or xenotime-stabilized zircon-type materials. The refractory materials can be used in the manufacture of glass and glass-ceramics. For example, the refractory materials, especially those that contain P2O5/R2O3 constituents, can be used as forming structures (“isopipes”) in the fusion process for making flat sheets of glass such as the glass sheets used as substrates in the manufacture of flat panel displays.

Abstract: Unlike conventional dental ceramic powder made by grinding, dental ceramic nanocrystals are formed by vaporization into individual particles. Tetragonal zirconia particles thus formed are not broken into pieces, and so do not transform to weaker monoclinic zirconia and weaker sintered products. The particles created by this approach can be much smaller, and dental prostheses sintered from this powder can be stronger and more realistic. For instance, the smaller size of sintered tetragonal zirconia crystals increases optical translucence by reducing scattering from birefringence, and the small average particle size and tight distribution of sizes and shapes can essentially eliminate pores in a sintered product. Cylindrical and spherical particles can be manufactured by this approach, whereas prior art dental ceramic particles were generally neither.

Abstract: A thermal barrier coating material that exhibits superior high-temperature crystal stability to YSZ, as well as a high degree of toughness and an excellent thermal barrier effect. Also provided are a thermal barrier coating, which has a ceramic layer formed using the thermal barrier coating material and exhibits excellent durability to heat cycling, and a turbine member and a gas turbine which are each provided with the thermal barrier coating. The thermal barrier coating material comprises mainly ZrO2 which contains Yb2O3 and Sm2O3 as stabilizers, wherein the amount of the stabilizers is not less than 2 mol % and not more than 7 mol %, and the amount of the Sm2O3 is not less than 0.1 mol % and not more than 2.5 mol %.

Abstract: A solid solution-comprising ceramic article useful in semiconductor processing, which is resistant to erosion by halogen-containing plasmas. The solid solution-comprising ceramic article is formed from a combination of yttrium oxide and zirconium oxide. In a first embodiment, the ceramic article includes ceramic which is formed from yttrium oxide at a molar concentration ranging from about 90 mole % to about 70 mole %, and zirconium oxide at a molar concentration ranging from about 10 mole % to about 30 mole %. In a second embodiment, the ceramic article includes ceramic which is formed from zirconium oxide at a molar concentration ranging from about 96 mole % to about 94 mole %, and yttrium oxide at a molar concentration ranging from about 4 mole % to about 6 mole %.

Abstract: A composite article includes a substrate and a protective layer disposed on the substrate. The protective layer has a silicon-aluminum-carbon-nitrogen solid solution composition and microstructure.

Abstract: To provide a process for producing high-purity highly oxidized refractory particles easily with good productivity by treating a spent refractory containing ZrO2 and Al2O3 to reduce components other than ZrO2 and Al2O3 to levels unproblematic for practical use as raw material for electrofused refractories and to increase the content of the ZrO2 and/or Al2O3 component. A process for producing refractory particles, which comprises introducing to and melting in a melting furnace both a spent refractory which contains, by mass % as chemical components, from 75 to 97% of ZrO2 and/or Al2O3, from 2 to 25% of SiO2, from 0.4 to 7% in total of Na2O, K2O and Li2O(Na2O+K2O+Li2O), at most 2% of CaO and at most 2% of MgO, and carbon particles in an amount of from 1 to 8% by outer mass percentage based on the spent refractory, and after the melting, tapping the melt while blowing compressed air against the melt to form refractory particles having the content of ZrO2 and/or Al2O3 increased.

Abstract: The present invention provides the use of a doped zirconia ceramic having a mean grain size of about 190 nm or less and consisting of the tetragonal zirconia crystallographic phase as a hydrothermally stable material or in an application that requires the use of a hydrothermally stable material. The present invention also provides a doped zirconia ceramic having a mean grain size of about 190 nm or less and consisting of tetragonal zirconia which does not undergo detectable tetragonal to monoclinic transformation during aging in moisture in an autoclave at a temperature of up to about 245° C. for up to 504 hours at a pressure of up to 7 bar.

Abstract: Dental articles are produced using relatively low sintering temperatures to achieve high density dental articles exhibiting strengths equal to and greater than about 700 MPa. Ceramic powders comprised of nanoparticulate crystallites are used to manufacture dental articles. The ceramic powders may include sintering agents, binders and other similar additives to aid in the processing of the ceramic powder into a dental article. The ceramic powders may be processed into dental articles using various methods including, but not limited to, injection molding, gel-casting, slip casting, or electroforming, hand, cad/camming and other various rapid prototyping methods. The ceramic powder may be formed into a suspension, pellet, feedstock material or a pre-sintered blank prior to forming into the dental article.

Abstract: A process for forming a coating on a substrate, such as a turbine engine component, is provided. The process comprises the steps of: providing a first rare earth oxide stabilized zirconia composition; providing a second composition selected from the group consisting of a yttria stabilized zirconia composition, a ceria stabilized zirconia composition, alumina, a chromia-alumina composition, a gadolinia stabilized zirconia composition, and mixtures thereof; blending the first rare earth oxide stabilized zirconia composition with the second composition to form a blended powder; and depositing the blended powder onto the substrate. Articles having the coating formed from the above process are also described.

Abstract: An article, such as a bucket, a blade, a nozzle, a vane, a strut, a fuel nozzle, a combustion casing, and a transition piece, the article having a damping coating comprising approximately 8 wt % to approximately 15 wt % Y2O3 and approximately 19 wt % to approximately 28 wt % Ta2O5 with the balanced weight of ZrO2 is presented.

Abstract: There is described a Ceramic Powder, a Ceramic Layer and a Layer System of Two Pyrochlore Phases and Oxides. Besides a good thermal insulation property, thermal insulation layer systems must also have a long lifetime of the thermal insulation layer. The layer system has a ceramic layer, which comprises a mixture of two pyrochlore phases.

Abstract: Methods are provided to form and stabilize high-? dielectric films by vapor deposition processes using metal-source precursors and titanium-based ?-diketonate precursors according to Formula I: Ti(L)x wherein: L is a ?-diketonate; and x is 3 or 4. Further provided are methods of improving high-? gate property of semiconductor devices by using titanium precursors according to Formula I. High-? dielectric film-forming lattices are also provided comprising titanium precursors according to Formula I.

Abstract: The present disclosure relates to a silica-based crucible material that includes, before sintering or firing, selected amounts of a thermal expansion stabilizer component (B2O3 and Ca2SiO4) which impart improved thermal shock resistance and enhanced ability to withstand repeated thermal cycling, to a sintered or fired crucible made of the material. An illustrative embodiment of the invention provides a crucible material whose chemical composition comprises, in weight %, about 91% to about 98% SiO2, about 1% to about 8% thermal stabilizer component, and up to about 1.0% of additional oxides including MgO, Al2O3 Fe2O3, CaO and ZrO2.

Abstract: The present invention relates to a sintered product elaborated from a starting charge containing 75-99% of zircon, in mass percentage based on the oxides and having the following average weight chemical composition, in mass percentages based on the oxides 60%?ZrO2?72.8%, 27%?SiO2?36%, 0.1%?B2O3+GeO2+P2O5+Sb2O3+Nb2O5+Ta2O5+V2O5, 0.1%?ZnO+PbO+CdO, B2O3+GeO2+P2O5+Sb2O3+Nb2O5+Ta2O5+V2O5+ZnO+PbO+CdO?5% 0% ?Al2O3+TiO2+MgO+Fe2O3+NiO+MnO2+CoO+CuO?5%, other oxides: ?1.5%, for a total of 100%. Notably used in a glass furnace.

Abstract: The inventive composition, according to a first embodiment, consists essentially of a cerium oxide and a zirconium oxide. According to a second embodiment, said composition is based on cerium oxide, zirconium oxide and at least one rare earth oxide other than cerium. After a first 4-hour period of calcination at 900 .C followed by a second 10-hour period of at 1000 .C, the specific surface variation thereof is 20% maximum in the first embodiment and 15% maximum in the second embodiment. The inventive composition can be used as a catalyst, i.e. in the treatment of waste gases from internal combustion engines.

Abstract: The invention relates to the field of synthetic materials and is industrially applicable in the manufacture of wear-resistant construction parts for use under conditions of elevated temperatures, loads, and aggressive media, for cutting and machining tools, and in medical equipment. The technical problem of optimization of the performance parameters of the material, including crack resistance, hardness, and wear resistance, is solved. The objective is achieved by the fact that a material based on zirconium dioxide, containing yttrium and obtained by directed crystallization from batch mixture melted in a cold container, contains at least two tetragonal phases whose axes of tetragonality are 80-90°. The components of the batch mixture for obtaining the material are contained in the following ratio (in mol %): yttrium oxide, 2.8-3.7; zirconium dioxide, the remainder.

Abstract: An electrostatic chuck that is a member for a semiconductor-manufacturing apparatus contains an yttrium oxide material containing first inorganic particles and second inorganic particles. The first inorganic particles form solid solutions in yttrium oxide, can be precipitated from yttrium oxide, and are present in grains of yttrium oxide. The second inorganic particles can form solid solutions in the first inorganic particles, are unlikely to form any solid solution in yttrium oxide, and are present at boundaries between the yttrium oxide grains. The first inorganic particles contain at least one of ZrO2 and HfO2. The second inorganic particles contain at least one selected from the group consisting of MgO, CaO, SrO, and BaO. The yttrium oxide material is produced in such a manner that solid solution particles are prepared by mixing and firing the first and second inorganic particles and are mixed with yttrium oxide and the mixture is fired.

Abstract: A subject of the invention relates to providing a powder for a translucent zirconia sintered body which is necessary for the production of a zirconia sintered body having a high sintered-body density and high strength and giving an excellent sense of translucency, without conducting any special sintering, such as HIP sintering. The invention relates to a technique for obtaining, through normal-pressure sintering, a translucent zirconia sintered body characterized by comprising zirconia which contains 2-4 mol % yttria as a stabilizer and has an alumina content of 0.2 wt % or lower, and by having a relative density of 99.8% or higher and a total light transmittance, as measured at a thickness of 1.0 mm, of 35% or higher. It is preferred that a powder containing 0-0.2 wt % alumina with a particle diameter of 0.01-0.5 ?m, having a BET specific surface area of 5-16 m2/g and an average particle diameter of 0.3-0.7 ?m, and having a rate of sintering shrinkage in normal-pressure sintering (??/?T; g/cm3·° C.) of 0.