Abstract: A positive electrode active material for nonaqueous electrolyte secondary batteries which allows the capacity of nonaqueous electrolyte secondary batteries to be increased and offers a smaller decrease in charge discharge cycle characteristics, and to provide a nonaqueous electrolyte secondary battery having such a positive electrode active material. A positive electrode active material for nonaqueous electrolyte secondary batteries according to the present invention includes a composite oxide containing Li, Ni, Co, Al, W and additive elements M, the proportion of Ni in the composite oxide being not less than 80 mol % relative to the total number of moles of the metal elements except Li, the additive elements M including at least either of an alkaline earth metal element and an alkali metal element except Li, and a tetravalent or higher valent element, the average valence of the additive elements M being not less than 3.6.

Abstract: A method of producing hydrogen gas comprises introducing gaseous water to an electrolysis cell comprising a positive electrode, a negative electrode, and a proton-conducting membrane between the positive electrode and the negative electrode. The proton-conducting membrane comprises an electrolyte material having an ionic conductivity greater than or equal to about 10?2 S/cm at one or more temperatures within a range of from about 150° C. to about 650° C. The gaseous water is decomposed using the electrolysis cell. A hydrogen gas production system and an electrolysis cell are also described.

Abstract: Disclosed herein is a non-flammable sodium-ion battery having a cathode and an anode and which uses an electrolyte that includes NaBF4 and a glyme solvent, where the battery has an average voltage of from 1.5 V to 6.0 V and has a coulombic efficiency after 5 charge/discharge cycles of at least 90%.

Abstract: A controlled oxidizing method is provided for preparing a high-performance nickel-rich lithium ion battery cathode material having a composition of LiNixM1-xO2, where 0.6<x<0.9, and M is one or more metals selected from the group consisting of Co, Mn, Fe, Ti, Zr, V, and Cr. The method comprises combining a water-soluble salt precursor of nickel and a water-soluble salt precursor of the one or more M metals with one or more oxidizing agents to form an aqueous solution. The aqueous solution is alkalized to a selected pH value to produce precipitated precursors. The precipitated precursors are mixed with a lithium precursor to form a lithiated precursor. The lithiated precursor is calcined to form the nickel-rich lithium ion battery cathode material.

Abstract: A device comprising one or more heat transfer laminates each including an electrode, a first dielectric layer on a first side of the electrode, and a second dielectric layer on a second side of the electrode; a plurality of flexible electrocaloric elements, each of the flexible electrocaloric elements including an electrocaloric material layer, a flexible electrode layer on the electrocaloric layer, one or more fixed portions each attached to one of heat transfer laminates, and a movable portion that is movable with respect to the one of the heat transfer laminates.

Abstract: The present disclosure relates to a positive active material for a lithium rechargeable battery and a lithium rechargeable battery including the same, which include a first compound represented by Chemical Formula 1 and a second compound represented by Chemical Formula 2, and a content of the first compound is 65 wt % or more based of the positive active material of 100 wt %. Lia1Nib1Coc1Mnd1M1e1M2f1O2-f1[??Chemical Formula 1] Lia2Nib2COc2Mnd2M3e2M4f2O2-f2[??Chemical Formula 2] Chemical Composition 1 and 2 of each composition and molar ratio is as defined in the specification. Each composition and molar ratio of Chemical Formula 1 and 2 is as defined in the specification.

Abstract: A solid electrolyte for an all-solid-state sodium battery, represented by formula: Na3?xSb1?x?xS4, wherein ? is selected from elements that provide Na3?xSb1?x?xS4 exhibiting a higher ionic conductivity than Na3SbS4, and x is 0<x<1.

Abstract: A cathode configured to use oxygen as a cathode active material includes: a porous film including a metal oxide, where a porosity of the porous film is about 50 volume percent to about 95 volume percent, based on a total volume of the porous film, and an amount of an organic component in the porous film is 0 to about 2 weight percent, based on a total weight of the porous film.

Abstract: A shaft, a wedge and a fulcrum plate connecting the shaft and wedge and having a transverse cross-section in one plane narrower than the shaft and a cross-section in an orthogonal plane wider than the transverse cross-section.

Abstract: Provided are processes for the production of particles for use as a precursor material for synthesis of Li-ion cathode active material of a lithium-ion cell comprising: a non-lithiated nickel oxide particle of the formula MOx wherein M comprises 80 at % Ni or greater and wherein x is 0.7 to 1.2, M optionally excluding boron in the MOx crystal structure; and a modifier oxide intermixed with, coated on, present within, or combinations thereof the non-lithiated nickel oxide particle, wherein the modifier oxide is associated with the non-lithiated nickel oxide such that a calcination at 500 degrees Celsius for 2 hours results in crystallite growth measured by XRD of 2 nanometers or less.

Abstract: In various embodiments, techniques for fabricating solid oxide fuel cells utilize setter plates composed of or having outer surfaces composed of materials unreactive with species found in the layers of the cell.

Abstract: Solid-state lithium ion electrolytes of lithium silicate based composites are provided which contain an anionic framework capable of conducting lithium ions. An activation energy for lithium ion migration in the solid state lithium ion electrolytes is 0.5 eV or less and room temperature conductivities are greater than 100.5 S/cm. Composites of specific formulae are provided and methods to alter the composite materials with inclusion of aliovalent ions shown. Lithium batteries containing the composite lithium ion electrolytes are also provided.

Abstract: A lithium positive electrode active material intermediate including less than 80 wt % spinel phase and a net chemical composition of LixNiyMn2-yO4-? wherein 0.9?x?1.1; 0.4?y?0.5; and 0.1??. Further, a process for the preparation of a lithium positive electrode active material with high tap density for a high voltage secondary battery where the cathode is fully or partially operated above 4.4 V vs. Li/Li+, comprising the steps of a)heating a precursor in a reducing atmosphere at a temperature of from 300° C. to 1200° C. to obtain a lithium positive electrode active material intermediate; b)heating the product of step a. in a non-reducing atmosphere at a temperature of from 300° C. to 1200° C.; wherein the mass of the product of step b. increases by at least 0.25% compared to the mass of the product of step a.

Abstract: Electrolytes and electrolyte additives for energy storage devices comprising a sulfonate ester compound are disclosed. The energy storage device comprises a first electrode and a second electrode, wherein at least one of the first electrode and the second electrode is a Si-based electrode, a separator between the first electrode and the second electrode, an electrolyte, and at least one electrolyte additive selected from a sulfonate ester compound.

Abstract: A magnetic material is constituted of a ferromagnetic or ferrimagnetic insulator in a double perovskite structure of Sr3-xAxOs1-yByO6 (0.5?x?0.5, ?0.5?y?0.5). A is an alkali metal or alkaline earth metal atom, and B is a transition metal atom, alkali metal atom, or alkaline earth metal atom). The insulator may be Sr3OsO6, where x=y=0 in the above formula. Sr3OsO6 is formed to have a cubic crystal structure where strontium atoms, osmium atoms, and oxygen atoms are arranged at lattice points.

Abstract: Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.

Abstract: An electrocaloric-based cooling system includes a solid electrolyte, which includes a silver conducting electrolyte sandwiched between a first electrode and a second electrode. The solid electrolyte when biased shows an electrocaloric effect.

Abstract: An oxide sintered body is characterized in that it comprises an oxide including an In element, a Zn element, a Sn element and a Y element and that a sintered body density is equal to or more than 100.00% of a theoretical density.

Abstract: A REBCO superconductor tape that can achieve a lift factor greater than or equal to approximately 3.0 or 4.0 in an approximately 3 T magnetic field applied perpendicular to a REBCO tape at approximately 30 K. In an embodiment, the REBCO superconductor tape can include a critical current density less than or equal to approximately 4.2 MA/cm2 at 77 K in the absence of an external magnetic field. In another embodiment, the REBCO superconductor tape can include a critical current density greater than or equal to approximately 12 MA/cm2 at approximately 30 K in a magnetic field of approximately 3 T having an orientation parallel to a c-axis.

Abstract: An oxide sintered body containing indium, hafnium, tantalum, and oxygen as constituent elements, in which when indium, hafnium, and tantalum are designated as In, Hf, and Ta, respectively, the atomic ratio of Hf/(In+Hf+Ta) is equal to 0.002 to 0.030, and the atomic ratio of Ta/(In+Hf+Ta) is equal to 0.0002 to 0.013.

Abstract: The purpose of the present invention is to easily provide at low cost, a cathode active material for non-aqueous electrolyte secondary batteries, which exhibits high particle strength and high weather resistance, while enabling achievement of excellent charge and discharge capacity and excellent output characteristics in cases where the cathode active material is used as a cathode material of a non-aqueous electrolyte secondary battery. A slurry of from 500 g/L to 2000 g/L is formed by adding water to a powder of a lithium nickel composite oxide represented by the general formula (A): LizNi1-x-yCoxMyO2, where 0.10?x?0.20, 0?y?0.10, 0.97?z?1.20, and M represents at least one element selected from among Mn, V, Mg, Mo, Nb, Ti and Al); the slurry is washed with water by stirring; and after filtration, the resulting material is subjected to a heat treatment at a temperature of from 120° C. to 550° C. (inclusive) in an oxygen atmosphere having an oxygen concentration of 80% by volume or more.

Abstract: In some examples, a fuel cell comprising a first electrochemical cell including a first anode and a first cathode; a second electrochemical cell including a second anode and a second cathode; and an interconnect configured to conduct a flow of electrons from the first anode to the second cathode, wherein the interconnect comprises a first portion and a second portion, wherein the first portion is closer to the anode than the second portion, and the second portion is closer to the cathode than the first portion, wherein the first portion comprises one or more of doped ceria, doped lanthanum chromite, and doped yttrium chromite, and wherein the second portion comprises one or more of a Co—Mn spinel and a ABO3 perovskite.

Abstract: A high-voltage positive electrode material for a lithium battery and a preparation method thereof are provided. The high-voltage positive electrode material for a lithium battery includes a material represented by the following formula (1): LiNi0.5-x-yMn1.5-x-yMg3xCr2yO4??(1) wherein x>0, y>0, and 0<3x+2y?0.1.

Abstract: A voltage nonlinear resistor ceramic comprises: a Zn oxide; a Co oxide; an R (specific rare earth) oxide; a Cr oxide; an M1 (Ca, Sr) oxide; an M2 (Al, Ga, In) oxide; and strontium titanate. When content of the Zn oxide is assumed to be 100 mole portion in terms of Zn, content of the Co oxide is 0.30 to 10 mole portion in terms of Co, content of the R oxide is 0.10 to 10 mole portion in terms of R, content of the Cr oxide is 0.01 to 2 mole portion in terms of Cr, content of the M1 oxide is 0.10 to 5 mole portion in terms of M1, content of the M2 oxide is 0.0005 to 5 mole portion in terms of M2, and content of the strontium titanate is 0.10 to 5 mole portion in terms of SrTiO3.

Abstract: The disclosed embodiments relate to the manufacture of a precursor co-precipitate material for a cathode active material composition. During manufacture of the precursor co-precipitate material, an aqueous solution containing at least one of a manganese sulfate and a cobalt sulfate is formed. Next, a NH4OH solution is added to the aqueous solution to form a particulate solution comprising irregular secondary particles of the precursor co-precipitate material. A constant pH in the range of 10-12 is also maintained in the particulate solution by adding a basic solution to the particulate solution.

Abstract: In a nonaqueous electrolyte secondary battery including a positive electrode, a negative electrode and a nonaqueous electrolytic solution, the nonaqueous electrolytic solution contains a nitrile compound having a chain saturated hydrocarbon group and a nitrile group, the number of carbon atoms in the nitrile compound is four or more, and the positive electrode contains a positive-electrode active material on the surface of which particles of a rare earth element compound are deposited in dispersed form.

Abstract: To provide an active material having high capacity and excellent cycle characteristics. An active material has a layered crystal structure and is expressed by a compositional formula (1) LiyNiaCobMncMdOx (1), where the element M is at least one kind of element selected from the group consisting of Al, Si, Zr, Ti, Fe, Mg, Nb, Ba, and V; 1.9?(a+b+c+d+y)?2.1; 1.05?y?1.35; 0<a?0.3; 0<b?0.25; 0.3?c?0.7; 0?d?0.1; and 1.9?x?2.1, and wherein 0.69?Ni?/Ni??0.85, where Ni? is the Ni composition amount at a center portion of the active material primary particle, and Ni? is the Ni composition amount in the vicinity of a surface (in a width of 30 nm from the surface).

Abstract: A production process for composite oxide expressed by a compositional formula: LiMn1-xAxO2, where “A” is one or more kinds of metallic elements other than Mn; and 0?“x”<1, obtained by preparing a raw-material mixture by mixing a metallic-compound raw material and a molten-salt raw material with each other, the metallic-compound raw material at least including an Mn-containing nitrate that includes one or more kinds of metallic elements in which Mn is essential, the molten-salt raw material including lithium hydroxide and lithium nitrate, and exhibiting a proportion of the lithium nitrate with respect to the lithium hydroxide (Lithium Nitrate/Lithium Hydroxide) that falls in a range of from 1 or more to 3 or less by molar ratio; reacting the raw-material mixture at 500° C. or less by melting it; and recovering the composite oxide being generated from the raw-material mixture that has undergone the reaction.

Abstract: A metal-oxide sintered body for a temperature sensor that can be installed in a combustion engine and components connected to the engine in order to sense temperature uses metal oxide. The metal-oxide sintered body has particles with large resistance values and particles with small resistance values mixed therein. The particles with the small resistance values may serve as a main resistance component in the temperature range of 0° C. to 500° C., and the particles with the large resistance values may contribute to the total resistance in proportion to the mixing ratio in the temperature range of 500° C. to 900° C. Thus, the metal-oxide sintered body enables a single sensor to measure all resistances, and can be used in an exhaust device or the like of a motor vehicle that requires temperature measurement over a wide range of temperatures.

Abstract: The present invention discloses a lithium-rich positive electrode material, a lithium battery positive electrode, and a lithium battery. The lithium-rich positive electrode material has a coating structure, where a general structural formula of a core of the coating structure is as follows: z[xLi2MO3·(1?x)LiMeO2]·(1?z)Li1+dMy2?dO, where in the formula, 0<x<1, 0<z<1, and 0<d<?; M is at least one of Mn, Ti, Zr, and Cr, Me is at least one of Mn, Co, Ni, Ti, Cr, V, Fe, Al, Mg, and Zr, and My is at least one of Mn, Ni, and Co; and a coating layer of the coating structure is a compound whose general formula is MmMz, where in the formula, Mm is at least one of Zn, Ti, Zr, and Al, and Mz is O or F. The lithium battery positive electrode and the lithium battery both include the lithium-rich positive electrode material.

Abstract: Disclosed are new compound semiconductors which may be used for solar cells or as thermoelectric materials, and their application. The compound semiconductor may be represented by a chemical formula: InxCo4Sb12-zSez, where 0<x?0.25 and 0.4<z?2.

Abstract: A sodium manganese composite oxide represented by Formula 1: NaxMayMnzMbvO2+d ??Formula 1 wherein, 0.2?x?1, 0<y?0.2, 0<z?1, 0?v<1, 0<z+v?1, ?0.3?d<1, Ma is an electrochemically inactive metal, and Mb is different from Ma and Mn, and is at least one transition metal selected from elements in Groups 4 to 12 of the periodic table of the elements.

Abstract: The present invention provides a method of preparing aluminum-doped zinc oxide (AZO) nanocrystals. In an exemplary embodiment, the method includes (1) injecting a precursor mixture of a zinc precursor, an aluminum precursor, an amine, and a fatty acid in a solution of a vicinal diol in a non-coordinating solvent, thereby resulting in a reaction mixture, (2) precipitating the nanocrystals from the reaction mixture, thereby resulting in a final precipitate, and (3) dissolving the final precipitate in an apolar solvent. The present invention also provides a dispersion. In an exemplary embodiment, the dispersion includes (1) nanocrystals that are well separated from each other, where the nanocrystals are coated with surfactants and (2) an apolar solvent where the nanocrystals are suspended in the apolar solvent. The present invention also provides a film. In an exemplary embodiment, the film includes (1) a substrate and (2) nanocrystals that are evenly distributed on the substrate.

Abstract: This invention relates to a ceramic composition, which is suitable for use in DOC and DPF for removing nitrogen oxide, carbon monoxide and unburned particles from exhaust gas systems of vehicles or for use in a thermistor temperature sensor for an industrial high-temperature environment similar thereto, and to a thermistor device manufactured using the composition. The ceramic composition is prepared by adding a perovskite phase having a perovskite crystalline structure represented by ABO3 with Sn of Group 4B or Sb or Bi of Group 5B, wherein A includes at least one element selected from among Groups 2A and 3A elements except for LA, and B includes at least one element selected from among transition metals of Groups 4A, 5A, 6A, 7A, 8A, 2B and 3B.

Abstract: Embodiments of the present disclosure include chemical compositions, structures, anodes, cathodes, electrolytes for solid oxide fuel cells, solid oxide fuel cells, fuel cells, fuel cell membranes, separation membranes, catalytic membranes, sensors, coatings for electrolytes, electrodes, membranes, and catalysts, and the like, are disclosed.

Abstract: A composite material for a temperature sensor and a method of manufacturing the temperature sensor using the composite material are provided. The composite material contains four or more kinds of metal oxides combined with highly insulating materials to produce a material with semiconductor-like properties to more accurately measure a temperature at high temperatures in the range of 500° C. and above. The sensor includes electrode wires having a predetermined diameter inserted into the metal oxide of the temperature sensor when the metal oxide is press-molded to form the temperature sensor. Through the connection of the electrode wires to the temperature sensor device, disconnection of the electrode wires from the device even at a high temperature.

Abstract: Provided is an iron-based superconducting material including an iron-based superconductor having a crystal structure of ThCr2Si2, and nanoparticles which are expressed by BaXO3 (X represents one, two, or more kinds of elements selected from a group consisting of Zr, Sn, Hf, and Ti) and have a particle size of 30 nm or less. The nanoparticles are dispersed in a volume density of 1×1021m?3 or more.

Abstract: A composite oxide sintered body includes In, Zn, and Sn, and has a relative density of 90% or more, an average crystal grain size of 10 ?m or less, and a bulk resistance of 30 m?cm or less, the number of tin oxide aggregate particles having a diameter of 10 ?m or more being 2.5 or less per mm2 of the composite oxide sintered body.

Abstract: A positive active material according to one embodiment of the present invention includes an internal bulk part and an external bulk part surrounding the internal bulk part and has a continuous concentration gradient of the metal composition from an interface between the internal bulk part and the external bulk part to the surface of the active material. The provided positive active material in which the metal composition is distributed in a continuous concentration gradient has excellent electrochemical characteristics such as a cycle life, capacity, and thermal stability.

Abstract: An anode active-material for rechargeable lithium batteries and methods of manufacturing the same. This includes preparing an anode active-material for rechargeable lithium batteries, including heat-treating a mixture of Li2CO3, MnO2, MgO, Al2O3 and Co3O4 at 900-1000° C. in air or oxygen for 10-48 hours, generating a lithium-containing oxide; generating metal-oxide nanoparticles MO (5-500 nm) (M represents Mg, Co or Ni, with a valence of 2); and dry or wet mixing 0.01-10 wt % of pulverized metal oxide nanoparticles with the lithium-containing oxide to form an anode active-material. Spinel type MgAl2O4 is substituted into a basic spinel-structure (Li1.1Mn1.9O4) for structural stability. Spinel type Co3O4 is substituted to improve electronic conductivity, improving battery performance.

Abstract: Novel anode materials including various compositions of vanadium-doped strontium titanate (SVT), and various compositions of vanadium- and sodium-doped strontium niobate (SNNV) for low- or intermediate-temperature solid oxide fuel cell (SOFCs). These materials offer high conductivity achievable at intermediate and low temperatures and can be used as the structural support of the SOFC anode and/or as the conductive phase of an anode. A method of making a low- or intermediate-temperature SOFC having an anode layer including SVT or SNNV is also provided.

Abstract: Provided are a mixed cathode active material having improved power characteristics and safety, and a lithium secondary battery including the same. More particularly, the present invention relates to a mixed cathode active material which may assist power in a low SOC range to widen an available state of charge (SOC) range and may simultaneously provide improved safety by blending substituted LFP, in which operating voltage is adjusted by substituting a portion of iron (Fe) with other elements such as titanium (Ti), in order to prevent a rapid increase in resistance of manganese (Mn)-rich having high capacity but low operating voltage in a low SOC range (e.g., a SOC range of 10% to 40%), and a lithium secondary battery including the mixed cathode active material.

Abstract: Disclosed are a positive active material composition for a rechargeable lithium battery, a positive electrode for a rechargeable lithium battery including the same, and a rechargeable lithium battery including the positive electrode. The positive active material composition for a rechargeable lithium battery includes a nickel-based positive active material having pH of greater than or equal to about 11; V2O5; an aqueous binder, and a conductive material.

Abstract: A composite metal oxide represented by the formula Ma1?xMbxMcO4+x/2, wherein Ma is at least one element selected from alkaline earth metals, Mb is at least one element selected from lanthanoids, Mc is at least one element selected from Mo and W, and x is from about 0.1 to about 0.5.

Abstract: A method for making a composite of cobalt oxide is disclosed. An aluminum nitrate solution is provided. Lithium cobalt oxide particles are introduced into the aluminum nitrate solution. The lithium cobalt oxide particles are mixed with the aluminum nitrate solution to form a mixture. A phosphate solution is added into the mixture to react with the aluminum nitrate solution and form an aluminum phosphate layer on surfaces of the lithium cobalt oxide particles. The lithium cobalt oxide particles with the aluminum phosphate layer formed on the surfaces thereof are heat treated to form a lithium cobalt oxide composite. The lithium cobalt oxide composite is electrochemical lithium-deintercalated at a voltage of Vx, wherein 4.5V<Vx?5V to form a cobalt oxide. The present disclosure also relates to a cobalt oxide and a composite of cobalt oxide.

Abstract: Because of the composition represented by General Formula: Li1+x+?Ni(1?x?y+?)/2Mn(1?x?y??)/2MyO2 (where 0?x?0.05, ?0.05?x+??0.05, 0?y?0.4; ?0.1???0.1 (when 0?y?0.2) or ?0.24???0.24 (when 0.2<y?0.4); and M is at least one element selected from the group consisting of Ti, Cr, Fe, Co, Cu, Zn, Al, Ge and Sn), a high-density lithium-containing complex oxide with high stability of a layered crystal structure and excellent reversibility of charging/discharging can be provided, and a high-capacity non-aqueous secondary battery excellent in durability is realized by using such an oxide for a positive electrode.

Abstract: A phase change material for use in a phase change memory device comprises germanium-antimony-tellurium-indium, wherein the phase change material comprises in total more than 30 at % antimony, preferably 5-16 at % germanium, 30-60 at % antimony, 25-51 at % tellurium, and 2-33% at % indium.

Abstract: A process for producing nanoparticles incorporating ions selected from groups 13, 16, and 11 or 12 of the periodic table, and materials produced by the process. In an embodiment, the process includes effecting conversion of a nanoparticle precursor composition comprising group 13, 16, and 11 or 12 ions to the material of the nanoparticles in the presence of a selenol compound. Other embodiments include a process for fabricating a thin film including nanoparticles incorporating ions selected from groups 13, 16, and 11 or 12 of the periodic table as well as a process for producing a printable ink formulation including the nanoparticles.

Abstract: An ink composition for forming a chalcogenide semiconductor film and a method for forming the same are disclosed. The ink composition includes a solvent, a plurality of metal chalcogenide nanoparticles and at least one selected from the group consisted of metal ions and metal complex ions. The metal ions and/or complex ions are distributed on the surface of the metal chalcogenide nanoparticles and adapted to disperse the metal chalcogenide nanoparticles in the solvent. The metals of the metal chalcogenide nanoparticles, the metal ions and the metal complex ions are selected from a group consisted of group I, group II, group III and group IV elements of periodic table and include all metal elements of a chalcogenide semiconductor material.

Abstract: A conductive sintered oxide which includes: a conductive crystal phase having a perovskite structure represented by (RE1-cSrc)MdO3, in which RE is a group of elements consisting of Yb and/or Lu and at least one element selected from Group IIIA elements excluding Yb, Lu and La, and M is a group of elements consisting of Al and at least one element selected from Groups IVA, VA, VIA, VIIA and VIII, a first insulating crystal phase represented by RE2O3, and a second insulating crystal phase represented by SrAl2O4. The conductive crystal phase has a coefficient c satisfying 0.18<c<0.50 and has a coefficient d satisfying 0.67?d?0.93. A content of a third insulating crystal phase represented by RE4Al2O9, the content of which may be zero, is smaller than the content of each of the first and second insulating crystal phases.