It relates to tantalum oxide particles containing molybdenum. The tantalum oxide particles preferably have a polyhedral shape, and the crystallite size of the tantalum oxide particles at 2=22.8 is preferably 160 nm or more. It also relates to a method for producing the tantalum oxide particles, the method including firing a tantalum compound in the presence of a molybdenum compound.

It relates to tantalum oxide particles containing molybdenum. The tantalum oxide particles preferably have a polyhedral shape, and the crystallite size of the tantalum oxide particles at 2=22.8 is preferably 160 nm or more. It also relates to a method for producing the tantalum oxide particles, the method including firing a tantalum compound in the presence of a molybdenum compound.

There is provided a piezoelectric substrate including a lithium-containing metal compound crystal such as a lithium tantalate (LT) crystal, wherein potassium is contained in the substrate and the distribution of potassium is approximately uniform as observed in the direction of the thickness of the substrate. There is also provided a piezoelectric substrate, wherein a peak coming from LiO lattice vibration and appearing around 380 cm.sup.1 is shifted to a high wave number side compared with that in an untreated piezoelectric substrate having a conductivity of 110.sup.15 S/cm or less in Raman spectra measured from the cross section direction.

A photochemical electrode includes: an optical absorption layer; a catalyst layer for oxygen evolution reaction over the optical absorption layer; and a conducting layer over the catalyst layer. A valance band maximum of the catalyst layer is higher than a valance band maximum of the optical absorption layer. A work function of the conducting layer is larger than a work function of the catalyst layer.

The present invention relates to a solid electrolyte comprising a sulfide-based compound and an all-solid-state battery applied therewith and, more particularly, to a solid electrolyte comprising a sulfide-based compound that is free of phosphorus (P) element but exhibits high ionic conductivity, and an all-solid-state battery applied therewith. The sulfide-based solid electrolyte and the all-solid-state battery applied therewith according to the present invention exhibit improved reactivity to moisture to prevent the generation of toxic gas, resulting in an improvement in safety and stability and do not reduce in ion conductivity even after being left in air, and the solid electrolyte is easy to handle and store thanks to the improved shelf stability thereof.

An oxide electrolyte sintered body with high lithium ion conductivity and a method for producing the same, which can obtain the oxide electrolyte sintered body with high lithium ion conductivity by sintering at lower temperature than ever before. The method for producing an oxide electrolyte sintered body may comprise the steps of: preparing crystal particles of a garnet-type ion-conducting oxide which comprises Li, H, at least one kind of element L selected from the group consisting of an alkaline-earth metal and a lanthanoid element, and at least one kind of element M selected from the group consisting of a transition element that can be 6-coordinated with oxygen and typical elements belonging to the Groups 12 to 15, and which is represented by a general formula (Li.sub.x3yz,E.sub.y,H.sub.z)L.sub.M.sub.O.sub. (where E is at least one kind of element selected from the group consisting of Al, Ga, Fe and Si, 3x3yz7, 0y<0.22, 0<z2.8, 2.53.5, 1.52.5, and 1113); preparing a lithium-containing flux; and sintering a mixture of the crystal particles of the garnet-type ion-conducting oxide and the flux by heating at 400 C. or more and 650 C. or less.

A process for synthesizing a Mn.sup.4+ doped phosphor of formula I by electrolysis is presented. The process includes electrolyzing a reaction solution comprising a source of manganese, a source of M and a source of A. One aspect relates to a phosphor composition produced by the process. A lighting apparatus including the phosphor composition is also provided. A.sub.x[MF.sub.y]:Mn.sup.4+ (I) where, A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MF.sub.y] ion; and y is 5, 6 or 7.

A solid electrolyte material contains Li, M, and X. M is at least one selected from metallic elements, and X is at least one selected from the group consisting of Cl, Br, and I. A plurality of atoms of X form a sublattice having a closest packed structure. An average distance between two adjacent atoms of X among the plurality of atoms of X is 1.8% or more larger than a distance between two adjacent atoms of X in a rock-salt structure composed only of Li and X.

Provided is a complex oxide that has a space group I-43d, has a high hydrogen content, contains almost no impurity phase, exhibits almost no aluminum substitution in the structure thereof, and is suitable for proton conductivity. This complex oxide is represented by a chemical formula Li.sub.7-x-yH.sub.xLa.sub.3Zr.sub.2-yM.sub.yO.sub.12 (M represents Ta and/or Nb, 3.2<x7y, and 0.25<y<2) and is a single phase of a garnet type structure belonging to a cubic system, and the crystal structure thereof is a space group I-43d.

Optical and electronic detection of chemicals, and particularly strong electron-donors, by 2H to 1T phase-based transition metal dichalcogenide (TMD) films, detection apparatus incorporating the TMD films, methods for forming the detection apparatus, and detection systems and methods based on the TMD films are provided. The detection apparatus includes a 2H phase TMD film that transitions to the 1T phase under exposure to strong electron donors. After exposure, the phase state can be determined to assess whether all or a portion of the TMD has undergone a transition from the 2H phase to the 1T phase. Following detection, TMD films in the 1T phase can be converted back to the 2H phase, resulting in a reusable chemical sensor that is selective for strong electron donors.