Materials that seamlessly transition from opaque to transparent or translucent, such as advanced geopolymer-based ceramics to glass structures, which can be directly and seamlessly bonded without the use of an intermediate adhesive or use of a frame are disclosed. That is, a GP-based ceramic to glass structure can be bonded directly and seamlessly and without any mechanical joints, connective tissue or adhesives such as caulking or epoxy. Such ceramic to glass materials can be prepared by sintering an engineered geopolymer with glass to form the geopolymer-based advanced ceramic-glass structure in which the interface is visually abruptly or in which the material is a graded composition with a controlled transition from one material to the other.

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.

Disclosed are fast high-temperature sintering systems and methods. A method of fabrication includes positioning a material at a distance of 0-1 centimeters from a first conductive carbon element and at a distance of 0-1 centimeters from a second conductive carbon element, heating the first conductive carbon element and the second conductive carbon element by electrical current to a temperature between 500° C. and 3000° C., inclusive, and fabricating a sintered material by heating the material with the heated first conductive carbon element and the heated second conductive carbon element for a time period between one second and one hour. Other variations of the fast high-temperature sintering systems and methods are also disclosed. The disclosed systems and methods can quickly fabricate unique structures not feasible with conventional sintering processes.

A method for fabricating a composite useful in a white light emitting device, includes mixing a phosphor and a filler to form a mixture; sintering the mixture (e.g., using spark plasma sintering) to form a composite; and annealing the composite to reduce oxygen vacancies and improve optical properties of the composite. Also disclosed is a white light emitting device including a laser diode or light emitting diode optically pumping the phosphor in the composite to produce white light. The composite fabricated using the method (and having. e.g., at most 50% phosphor by weight) can (1) reduce an operating temperature of the phosphor by 55 degrees, (2) increase an external quantum efficiency (e.g., by at least 15%) of the white light emitting device, and (3) result in color points and quality of the white light that is equal to or improved, as compared to without the filler.

In an embodiment a conversion element includes a first phase and a second phase, wherein the first phase comprises lutetium, aluminum, oxygen and a rare-earth element, wherein the second phase comprises Al.sub.2O.sub.3 single crystals, and wherein the conversion element comprises at least one groove.

Provided is a dielectric composition exhibiting a high specific dielectric constant and a high resistivity even when fired in a reducing atmosphere. The dielectric composition contains a composite oxide having a composition represented by (Sr.sub.xBa.sub.1-x).sub.yNb.sub.2O.sub.5+y, the crystal system of the composite oxide is tetragonal, and y in the composition formula is smaller than 1.

The present invention relates to a light-transmitting ceramic sintered body which contains air voids having pore diameters of 1 μm or more but less than 5 μm at a density within the range of from 10 voids/mm.sup.3 to 4,000 voids/mm.sup.3 (inclusive), while having a closed porosity of from 0.01% by volume to 1.05% by volume (inclusive). With respect to this light-transmitting ceramic sintered body, a test piece having a thickness of 1.90 mm has an average transmittance of 70% or more in the visible spectrum wavelength range of 500-900 nm, and the test piece having a thickness of 1.90 mm has a sharpness of 60% or more at a comb width of 0.5 mm.

Provided are a piezoelectric ceramics which does not contain lead, has small temperature dependence of a piezoelectric constant within an operating temperature range, and has high density, a high mechanical quality factor, a satisfactory piezoelectric constant, and a small surface roughness, and a method of manufacturing the piezoelectric ceramics. The method of manufacturing a piezoelectric ceramics is characterized by including: sintering a compact containing a raw material at 1,000° C. or more to obtain a sintered compact; abrading the sintered compact; and annealing the abraded sintered compact at a temperature of 800° C. or more and less than 1,000° C.

Disclosed is a plastic semiconductor material and a preparation method thereof. The semiconductor material comprises an argentite-based compound represented by the following formula (I): Ag.sub.2-δX.sub.δS.sub.1-ηY.sub.η(I), in which 0≤δ<0.5, 0≤η<0.5, X is at least one of Cu, Au, Fe, Co, Ni, Zn, Ti, or V, and Y is at least one of N, P, As, Sb, Se, Te, O, Br, Cl, I, or F. The material can withstand certain deformations, similar to organic materials, and has excellent semiconductor properties with adjustable electrical properties, thereby enabling the preparation of high-performance flexible semiconductor devices.

A garnet-structure complex oxide powder having formula (1) is prepared by adding an aqueous solution containing (a) Tb ion, an aqueous solution containing (b) Al ion, and an aqueous solution containing (c) Sc ion to a co-precipitating aqueous solution, to induce a co-precipitate of components (a), (b) and (c), filtering, heat drying and firing the co-precipitate.
(R.sub.1-xSc.sub.x).sub.3(A.sub.1-ySc.sub.y).sub.5O.sub.12  (1)
R is yttrium or a lanthanoid element, typically Tb, A is a Group 13 element, typically Al, x and y are 0<x<0.08 and 0.004<y<0.16.