Abstract: A method for manufacturing a gallium nitride semiconductor device includes: preparing a gallium nitride wafer; forming an epitaxial growth film on the gallium nitride wafer to provide a processed wafer having chip formation regions; perform a surface side process on a one surface side of the processed wafer; removing the gallium nitride wafer and dividing the processed wafer into a chip formation wafer and a recycle wafer; and forming an other surface side element component on an other surface side of the chip formation wafer.

Abstract: Provided are dielectric thin-film structures and electronic devices including the same. The dielectric thin-film structure includes a substrate, and a dielectric layer provided on the substrate. The dielectric layer including a tetragonal crystal structure, and crystal grains including a proportion of the crystal grains preferentially oriented such that at least one of a <hk0>, <h00>, or <0k0> direction of a crystal lattice is parallel to or forms an angle of less than 45 degrees an out-of-plane orientation.

Abstract: A quantum bit device according to the present invention includes a first quantum bit substrate 10 which includes a first superconductive wiring 13 disposed to have a magnetically coupled portion with a first superconductive magnetic flux quantum bit 14 on a surface thereof, a second quantum bit substrate 11 which includes a second superconductive wiring 13 disposed to have a magnetically coupled portion with a second superconductive magnetic flux quantum bit 14 on a surface thereof, and a base substrate 12 which includes a third superconductive wiring 13 configured by two superconductive wirings extending parallel to each other on a surface thereof.

Abstract: A perpendicular spin orbit torque (SOT) memory device includes an electrode having a spin orbit torque material, where the SOT material includes iridium and manganese and a perpendicular magnetic tunnel junction (pMTJ) device on a portion of the electrode. The pMTJ device includes a free magnet structure electrode, a fixed layer and a tunnel barrier between the free layer and the fixed layer and a SAF structure above the fixed layer. The Ir—Mn SOT material and the free magnet have an in-plane magnetic exchange bias.

Abstract: Transparent composite pane for safety applications. The composite pane is composed of multiple layers which are arranged behind one another. At least one of the layers is composed of, a plate or plates arranged in a mosaic or in series, of monocrystalline magnesium aluminate spinel.

Abstract: A perovskite manganese oxide thin film formed on a substrate that allows a first order phase transition and has A-site ordering. The thin film contains Ba and a rare earth element in the A sites of a perovskite crystal lattice and has an (m10) orientation for which m=2n, and 9?n?1. A method for manufacturing the film includes forming in a controlled atmosphere using laser ablation an atomic layer or thin film that assumes a pyramidal structure having oxygen-deficient sites in a plane containing the rare earth element and oxygen; and filling the oxygen-deficient sites with oxygen. The controlled atmosphere has an oxygen partial pressure controlled to a thermodynamically required value for creating oxygen deficiencies and contains a gas other than oxygen, and has a total pressure that is controlled to a value at which the A sites have a fixed compositional ratio.

Abstract: An article including a perovskite manganese oxide thin film is composed of a substrate; and a perovskite manganese oxide thin film formed on the substrate and having an orientation that is an (m10) orientation where 19?m?2. When m is 2 the perovskite manganese oxide thin film has a (210) orientation. The invention provides a perovskite manganese oxide thin film having a transition temperature at room temperature or above, which is higher than that of the bulk oxide, by exploiting the substrate strain and the symmetry of the crystal lattice.

Abstract: The present invention provides methods of protecting a surface of an aluminum nitride substrate. The substrate with the protected surface can be stored for a period of time and easily activated to be in a condition ready for thin film growth or other processing. In certain embodiments, the method of protecting the substrate surface comprises forming a passivating layer on at least a portion of the substrate surface by performing a wet etch, which can comprise the use of one or more organic compounds and one or more acids. The invention also provides aluminum nitride substrates having passivated surfaces.

Abstract: A method for improving the growth morphology of (Ga,Al,In,B)N thin films on nonpolar or semipolar (Ga,Al,In,B)N substrates, wherein a (Ga,Al,In,B)N thin film is grown directly on a nonpolar or semipolar (Ga,Al,In,B)N substrate or template and a portion of the carrier gas used during growth is comprised of an inert gas. Nonpolar or semipolar nitride LEDs and diode lasers may be grown on the smooth (Ga,Al,In,B)N thin films grown by the present invention.

Abstract: An article including a perovskite manganese (Mn) oxide thin film, includes a substrate having an oriented perovskite structure that is (m10) oriented, where 19?m?2, and having an [100] axis direction; and a perovskite manganese (Mn) oxide thin film having a perovskite crystal lattice containing barium Ba and a rare earth element Ln in A sites of the perovskite crystal lattice, the perovskite manganese (Mn) oxide thin film being formed on the substrate so as to cover at least part of a surface of the substrate, and having atomic planes stacked in a pattern of LnO—MnO2—BaO—MnO2-LnO . . . in the [100] axis direction of the substrate. The perovskite manganese (Mn) oxide thin film provided thoroughly exploits the resistance changes caused by charge and orbital ordering in the perovskite manganese oxide.

Abstract: A coated article includes a substrate and a first coating formed over at least a portion of the substrate. The first coating includes a mixture of oxides including oxides of at least two of P, Si, Ti, Al and Zr. A photoactive functional coating is formed over at least a portion of the first coating. In one embodiment, the functional coating includes titania.

Abstract: An oxide superconducting thin film includes a substrate having a single crystal structure, the main face of the substrate and a crystal face of the single crystal structure having an angle therebetween; an intermediate layer formed on the main face of the substrate and having an axis oriented in a direction perpendicular to the crystal face; and a superconducting layer formed on the intermediate layer and containing, as a main component, an oxide superconductor having a c-axis oriented in a direction perpendicular to the surface of the intermediate layer. A superconducting fault current limiter and a method of manufacturing an oxide superconducting thin film are also provided.

Abstract: Some aspects of the invention provide an oxide substrate having a flat surface at the atomic layer level, and suited to forming a thin film of a perovskite manganese oxide. One aspect of the invention provides a single-crystal oxide substrate 10 having a single-crystal supporting substrate 1 of (210)-oriented SrTiO3 and a single-crystal underlayer 2 of (LaAlO3)0.3-(SrAl0.5Ta0.5O3)0.7, which is LSAT, formed on the (210) plane surface of the supporting substrate. In another aspect of the present invention, the LSAT underlayer 2A is formed in an amorphous state. Other aspects of the invention are also disclosed.

Abstract: An article including a perovskite manganese oxide thin film is composed of a substrate; and a perovskite manganese oxide thin film formed on the substrate and having an orientation that is an (m10) orientation where 19?m?2. When m is 2 the perovskite manganese oxide thin film has a (210) orientation. The invention provides a perovskite manganese oxide thin film having a transition temperature at room temperature or above, which is higher than that of the bulk oxide, by exploiting the substrate strain and the symmetry of the crystal lattice.

Abstract: Disclosed herein is a nanocrystal-metal oxide complex. The nanocrystal of the nanocrystal-metal oxide complex is substituted with two or more different types of surfactants which are miscible with a metal oxide precursor and enable maintenance of luminescent and electrical properties of the nanocrystal. The nanocrystal-metal oxide complex exhibits superior optical and chemical stability and secures high luminescent efficiency of the nanocrystal. Accordingly, when the nanocrystal-metal oxide complex is used as a luminescent material of an electroluminescent device, it can improve luminescent efficiency and reliability of products. Further disclosed herein is a method for preparing the nanocrystal-metal oxide complex.

Abstract: A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

Abstract: A method for forming a graphene layer is disclosed herein. The method includes establishing an insulating layer on a substrate such that at least one seed region, which exposes a surface of the substrate, is formed. A seed material in the seed region is exposed to a carbon-containing precursor gas, thereby initiating nucleation of the graphene layer on the seed material and enabling lateral growth of the graphene layer along at least a portion of a surface of the insulating layer.

Abstract: In a cold gas spraying method, a gas jet (15) into which particles (19) are introduced is generated with the aid of a cold gas spray gun (20). The kinetic energy of the particles (19) results in a layer being formed on a substrate (13). The substrate is provided with a structured texture (24) which is transferred to the layer (20) that is formed. The method makes it advantageously possible to produce a high-temperature superconducting layer on the substrate (13) by selecting an appropriate particle (19) composition. The process can be additionally supported using a heating device (25) in a subsequent thermal treatment step.

Abstract: Methods and structures for monolithically integrating monocrystalline silicon and monocrystalline non-silicon materials and devices are provided. In one structure, a semiconductor structure includes a silicon substrate and a first monocrystalline semiconductor layer disposed over the silicon substrate, wherein the first monocrystalline semiconductor layer has a lattice constant different from a lattice constant of relaxed silicon. The semiconductor structure further includes an insulating layer disposed over the first monocrystalline semiconductor layer in a first region, a monocrystalline silicon layer disposed over the insulating layer in the first region, and a second monocrystalline semiconductor layer disposed over at least a portion of the first monocrystalline semiconductor layer in a second region and absent from the first region. The second monocrystalline semiconductor layer has a lattice constant different from the lattice constant of relaxed silicon.

Abstract: One embodiment is a method for manufacturing a stacked oxide material, including the steps of forming an oxide component over a base component; forming a first oxide crystal component which grows from a surface toward an inside of the oxide component by heat treatment, and leaving an amorphous component just above a surface of the base component; and stacking a second oxide crystal component over the first oxide crystal component. In particular, the first oxide crystal component and the second oxide crystal component have common c-axes. Same-axis (axial) growth in the case of homo-crystal growth or hetero-crystal growth is caused.

Abstract: The subject of the invention is a material comprising a substrate coated on at least one portion of at least one of its faces with a coating comprising photocatalytic titanium oxide, characterized in that said substrate and/or a coating placed between said substrate and said coating comprising photocatalytic titanium oxide comprises at least one compound capable of converting radiation having a wavelength in the visible or infrared range to radiation having a wavelength in the ultraviolet range.

Abstract: A method which has a step of growing a thermostable-state ZnO-based single crystal on a ZnO single crystal substrate at a growth temperature that is equal to or greater than 600° C. and less than 900° C. by using a metalorganic compound containing no oxygen and water vapor based on an MOCVD method.

Abstract: This invention disclosure describes methods for the fabrication of metal oxide films on surfaces by topotactic anion exchange, and laminate structures enabled by the method. A precursor metal-nonmetal film is deposited on the surface, and is subsequently oxidized via topotactic anion exchange to yield a topotactic metal-oxide product film. The structures include a metal-oxide layer(s) and/or a metal-nonmetal layer(s).

Abstract: A method of preparing an n-type epitaxial layer of aluminum nitride conductively doped with germanium comprises directing a molecular beam of aluminum atoms onto the growth surface of a substrate that provides an acceptable lattice match for aluminum nitride; directing a molecular beam of activated nitrogen to the growth surface of the substrate; and directing a molecular beam of germanium to the growth surface of the substrate; while maintaining the growth surface of the substrate at a temperature high enough to provide the surface mobility and sticking coefficient required for epitaxial growth, but lower than the temperature at which the surface would decompose or the epitaxial layer disassociate back into atomic or molecular species.

Abstract: Compositions comprising a single-phase rare-earth dielectric disposed on a substrate. Embodiments of the present invention provide the basis for high-K gate dielectrics in conventional integrated circuits and high-K buried dielectrics as part of a semiconductor-on-insulator wafer structure.

Abstract: Atomic layer epitaxy (ALE) is applied to the fabrication of new forms of rare-earth oxides, rare-earth nitrides and rare-earth phosphides. Further, ternary compounds composed of binary (rare-earth oxides, rare-earth nitrides and rare-earth phosphides) mixed with silicon and or germanium to form compound semiconductors of the formula RE—(O, N, P)—(Si,Ge) are also disclosed, where RE=at least one selection from group of rare-earth metals, O=oxygen, N=nitrogen, P=phosphorus, Si=silicon and Ge=germanium. The presented ALE growth technique and material system can be applied to silicon electronics, opto-electronic, magneto-electronics and magneto-optics devices.

Abstract: A Bi4Ti3O12 nanoplate, an array of such Bi4Ti3O12 nanoplate and their making methods as well as their applications are provided. Using a vapor phase growth method, a flux layer of VOx is deposited on a SrTiO3 (001) faced substrate and then Bi4Ti3O12 is deposited on the flux layer. A Bi4Ti3O12 single crystal nanoplate is formed standing up on the flux layer in the form of a rectangular solid whose independent three sides are crystallographically oriented in directions coincident with particular crystallographic directions of the single crystal substrate, respectively. The nanoplates as a nanostructure grown by the bottom-up method are substantially fixed in shape and are densely arrayed not in contact with one another, and are applicable to a low-cost ferroelectric memory and the like.

Abstract: A method of fabricating a large substrate with a locally integrated single crystalline silicon layer is provided. The method includes: forming a buffer layer on a support plate; separately fabricating a single crystalline silicon layer; attaching the single crystalline silicon layer having a predetermined thickness, which is separately fabricated, to a predetermined portion in the support plate; forming a non-single crystalline silicon layer having a predetermined thickness to cover the single crystalline silicon layer and the buffer layer; and processing the non-single crystalline silicon layer to expose a surface of the non-single crystalline silicon layer and to level the surface of the non-single crystalline silicon layer with a surface of the amorphous silicon layer.

Abstract: A surface-treated steel sheet is disclosed, including a zinc based plated steel sheet having thereon a surface-treated film containing titanium, nickel, aluminum and fluorine and having a film thickness of from 0.05 to 1.0 ?m, the surface-treated film having a titanium deposition amount of from 0.01 to 0.5 g/m2 and containing from 0.01 to 5 parts by mass of nickel, from 0.1 to 25 parts by mass of aluminum and from 1 to 500 parts by mass of fluorine relative to 100 parts by mass of titanium. This surface-treated steel sheet does not contain hexavalent chromium in the film thereof at all and has excellent heat discoloration resistance, corrosion resistance and resistance to blackening.

Abstract: A modified platinum group metal coating composition comprising a phase having a solid solution face-centered cubic (fcc) crystal structure, rich in platinum group materials. In order to be effective, the platinum group metal coating material was modified based on the chemical composition and chemical activity of the substrate material. The platinum group metal coating material was modified to include, in solid solution, elements of the superalloy substrate, specifically nickel (Ni) and cobalt (Co). Depending on the substrate material, the modified platinum group metal coating material may not even include Ni or Co, but may be modified to include amounts of different elements that are consistent with the chemical composition of the substrate. The modified platinum metal coating material also includes aluminum (Al). The composition may include small amounts of a second phase isolated within the fcc phase matrix.

Abstract: A method of making tantalum structures, including, creating a tantalum layer disposed on a first layer region of a first layer and on a second layer region of a second layer. The tantalum layer has a substantially bcc-phase tantalum region on the first layer region, and a non-bcc-phase tantalum region on the second layer region.

Abstract: Methods of forming lanthanum nickel oxide (LaNiO3) layers with precursor formation solutions are disclosed, along with devices made from such solutions. Also disclosed are methods for making the formation solutions using lanthanum, nickel, and a diol. The present invention enables the manufacture of LaNiO3 layers at low cost, with good resistivity properties, and a surface morphology suitable for interfacing to a ferro-electric material.

Abstract: The metal film of the present invention is a dense film of a single crystal that has very low surface roughness and very good crystal orientation because an arithmetic mean roughness of the surface is not larger than 2 nm and a (111) peak intensity of X-ray diffraction is not less than 20 times the sum of all other peaks. Also the metal oxide film of the present invention is a dense film that includes less oxygen defects and almost no voids therein because a content of a non-oxidized metal is not higher than 1 mole % of a metal component that constitutes the metal oxide and a packing density is 0.98 or higher.

Abstract: A method of forming a composite structure includes: (1) providing first and second sintered bodies containing first and second multicomponent metallic oxides having first and second identical crystal structures that are perovskitic or fluoritic; (2) providing a joint material containing at least one metal oxide: (a) containing (i) at least one metal of an identical IUPAC Group as at least one sintered body metal in one of the multicomponent metallic oxides, (ii) a first row D-Block transition metal not contained in the multicomponent metallic oxides, and/or (iii) a lanthanide not contained in the multicomponent metallic oxides; (b) free of metals contained in the multicomponent metallic oxides; (c) free of cations of boron, silicon, germanium, tin, lead, arsenic, antimony, phosphorus and tellurium; and (d) having a melting point below the sintering temperatures of the sintered bodies; and (3) heating to a joining temperature above the melting point and below the sintering temperatures.

Abstract: A method for manufacturing single crystal ceramic powder is provided. The method includes a powder supply step for supplying powder consisting essentially of ceramic ingredients to a heat treatment area with a carrier gas, a heat treatment step for heating the powder supplied to the heat treatment area at temperatures required for single-crystallization of the powder to form a product, and a cooling step for cooling the product obtained in the heat treatment step to form single crystal ceramic powder. The method provides single crystal ceramic powder consisting of particles with a very small particle size and a sphericity being 0.9 or higher.

Abstract: The invention is directed to a coated metal fluoride crystals that are resistant to laser-induced damage by a below 250 nm UV laser beam; methods of making such coated crystals, and the use of such coated crystals. The method includes the steps of providing an uncoated metal fluoride crystal of general formula MF2, where M is beryllium, magnesium, calcium, strontium and barium, and mixtures thereof, and coating the uncoated metal fluoride crystal with a coating of a selected material to thereby form a coated metal material resistant to laser induced damage. Preferred coating materials include MgF2, MgF2 doped fused silica and fluorine doped fused silica.

Abstract: A spinel composition of the invention includes a monocrystalline lattice having a formula Mg1-w?wAlx-y?yOz, where w is greater than 0 and less than 1, x is greater than 2 and less than about 8, y is less than x, z is equal to or greater than about 4 and equal to or less than about 13, ? is a divalent cationic element having an ionic radius greater than divalent magnesium, and ? is a trivalent cationic element having an ionic radius greater than trivalent aluminum. The monocrystalline lattice has tetrahedral and octahedral positions, and most of the magnesium and ? occupy tetrahedral positions. In one embodiment, the molar ratio of aluminum to the amount of magnesium, ? and ? can be controlled during growth of the monocrystalline lattice thereby forming a spinel substrate suitable for heteroepitaxial growth of III-V materials. A method of the invention, includes forming a monocrystalline lattice of a spinel composition.

Abstract: A method for producing a bonded article composed of a first substrate, a second substrate, and a bonding layer through which the first and second substrates are bonded to one another includes the steps of interposing a water-based bonding agent between the first and second substrates, and forming the bonding layer by heating the water-based bonding agent. The water-based bonding agent contains an alkali metal element, and has a water-soluble compound dissolved therein. The water-soluble compound produces a composite oxide by heating.

Abstract: A zinc oxide crystal growth substrate is disclosed. The zinc oxide crystal growth substrate includes a thin layer of single crystal zinc oxide deposited on an self supporting substrate surface by a chemical deposition process. The chemical deposition process is selected from RF sputtering, CVD (chemical vapor deposition), MOCVD (metal organic chemical vapor deposition), spin coating, electrophoresis, and hydrothermal growth processes. The self supporting substrate may be amorphous, polycrystalline, or crystalline. The thin layer of zinc oxide has a crystal lattice which permits the crystal growth of a crystal compatible with zinc oxide. The compatible crystal has a lattice parameter within about 5% of a corresponding lattice parameter of the zinc oxide.

Abstract: A substrate including a base substrate, an interfacial bonding layer disposed on the base substrate, and a thin film adaptive crystalline layer disposed on the interfacial bonding layer. The interfacial bonding layer is solid at room temperature, and is in liquid-like form when heated to a temperature above room temperature. The interfacial bonding layer may be heated during epitaxial growth of a target material system grown on the thin film layer to provide the thin film layer with lattice flexibility to adapt to the different lattice constant of the target material system.

Abstract: A coated cubic boron nitride (cBN) sintered body most suitable for a cutting tool having excellent resistance to wear and heat in the high-speed cutting of steel has been developed. The sintered body comprises (a) a base material made of a sintered body comprising at least 99.5 vol. % cBN and (b) a hard coating 0.1 to 10 &mgr;m in thickness formed on at least part of the surface of the base material by the PVD method. It is desirable that the hard coating comprise at least one compound layer consisting mainly of (a) at least one metal element selected from Al and the IV a-group elements and (b) at least one element selected from C, N, and O. It is desirable to provide between the base material and the hard coating an intermediate layer comprising a compound consisting mainly of boron and at least one metal element selected from the IV a-group elements.

Abstract: A ceramic material having particular utility as a thermal insulating or thermal barrier coating on metallic substrates is provided. The ceramic material broadly comprises at least one lanthanide sesquioxide and the balance comprising a first oxide selected from the group consisting of zirconia, ceria, and hafnia. The lanthanide sesquioxide has a formula A2O3 where A is selected from the group consisting of La, Pr, Nd, Sm, Eu, Tb, In, Sc, Y, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof. The present invention also broadly relates to an article having a metal substrate and a thermal barrier coating as discussed above.

Abstract: A high power ferrite microwave phase shifter that is both compact and low cost. The ferrite phase shifter includes a waveguide having a first cylinder and a second cylinder, the radius of the second cylinder being less than the radius of the first cylinder. The second cylinder is disposed within the first cylinder such that the two cylinders have a common axis of symmetry. The waveguide includes a first septum formed as a disk and disposed within the second cylinder. The disk has a pie-shaped aperture formed therethrough and is centrally disposed within the second cylinder so that the two cylinders and the disk share the same axis of symmetry. The second cylinder has an opening formed therethrough that is aligned with the pie-shaped aperture. The waveguide further includes a second septum that extends from the first cylinder to the disk center while bisecting the pie-shaped aperture, thereby separating an input from an output of the ferrite phase shifter.

Abstract: A silicon carbide epitaxial film, grown on an offcut surface of a SiC crystalline substrate of hexagonal crystal form, having an offcut angle of from about 6 to about 10 degrees, toward the <1{overscore (1)}00> crystalline direction of the substrate. The resultant silicon carbide epitaxial film has superior morphological and material properties.

Abstract: In a method of growing a ZnO-containing compound semiconductor single crystal, on a compound single crystal layer of a hexagonal crystal structure having a plurality of (0001) surfaces aligned in a sequence of terraces along a direction of a-axis, a ZnO-containing compound single crystal of a hexagonal crystal structure is grown, having an inclination from the c-axis toward the direction of the a-axis.

Abstract: A superconducting laminated oxide substrate, which comprises a laminate a layer of a superconducting oxide crystal substrate made of a superconducting oxide single crystal or a superconducting oxide polycrystal and a layer of a reinforcing crystal substrate, prevents cracks from occurring in the superconducting oxide crystal substrate due to the heat treatment conducted for the purpose of forming an insulation film or a conductor film, and provides easy connectivity between electrodes and wiring formed on substrates located at upper and lower positions.

Abstract: A group III nitride compound semiconductor device has a substrate and an AlN single crystal layer formed on the substrate. The AlN single crystal layer has a thickness of from 0.5 to 3 &mgr;m and has a substantially flat surface. The half-value width of an X-ray rocking curve of the AlN single crystal layer is not longer than 50 sec. In another device, a group III nitride compound semiconductor layer having a thickness of from 0.01 to 3.2 &mgr;m is grown at a temperature of from 1000 to 1180° C. on a sapphire substrate having a surface nitride layer having a thickness of not larger than 300 Å.

Abstract: The invention aims to provide a hard film which is improved in high-temperature corrosion resistance without impairing high sliding characteristics (wear resistance, low frictional coefficient) inherent in a titanium nitride thin film and which is suitable for a slide member such as a bearing or a seal used in rotary machines operated at a high temperature, such as a steam turbine and a gas turbine. For attaining this aim, the invention provides a Cr-containing titanium nitride film which is composed of a nitride containing Ti and Cr as main components, the crystal particles thereof having a face-centered cubic crystal structure, and the crystal thereof being highly oriented toward (200) face.

Abstract: Pulsed light is irradiated to an amorphous base material, to produce therein one or more single crystals or polycrystals having nonlinear characteristic advantageous for light communication and laser technique. An external field such as electric field or magnetic field may be applied to the amorphous material, or a seed crystal or crystalline substrate may be used to promote crystallization from a contact interface between the amorphous material and the seed crystal or crystalline substrate.

Abstract: The metal film of the present invention is a dense film of a single crystal that has very low surface roughness and very good crystal orientation because an arithmetic mean roughness of the surface is not larger than 2 nm and a (111) peak intensity of X-ray diffraction is not less than 20 times the sum of all other peaks. Also the metal oxide film of the present invention is a dense film that includes less oxygen defects and almost no voids therein because a content of a non-oxidized metal is not higher than 1 mole % of a metal component that constitutes the metal oxide and a packing density is 0.98 or higher.