Disclosed herein are embodiments of composite hexagonal ferrite materials formed from a combination of Y phase and Z phase hexagonal ferrite materials. Advantageously, embodiments of the material can have a high resonant frequency as well as a high permeability. In some embodiments, the materials can be useful for magnetodielectric antennas.

The invention relates to a method for producing an alumina based abrasive particle (1), comprising at least the following steps: forming a sol as a solution or dispersion of alumina particles, gelling the sol by adding gelling agents, forming shaped bodies from the gel using an additive procedure, drying and firing the shaped bodies while retaining the previously achieved geometry of the abrasive particles. Hereby, it is provided that an optically binding binder is added to the sol and/or the gel, the gel is applied additively layer by layer and the binder is set using electromagnetic radiation so as to form the shaped bodies. The produced abrasive particle may be formed, in particular, by six intersecting or overlapping triangular volume regions.

The present invention relates to an alpha alumina having a high purity, a high density and a low surface area and particularly, to a method to produce such an alpha alumina as well as to the use of the alpha alumina in sapphire production or the production of composite and ceramic bodies.

Systems, devices, and techniques for manufacturing a crystalline material (e.g., large crystal material) through the solid state conversion of a polycrystalline material are described. A device may be configured to concurrently heat a volume of ribbon, such as an alumina ribbon, using multiple heat sources. For example, a first heat source may heat a first volume of the ribbon and a second heat source may concurrently heat a second volume, for example, within the first volume, where the ribbon may comprise polycrystalline material. The concurrent heating may drive grain growth in the polycrystalline material in at least the second volume, which may convert the polycrystalline material to crystalline material having one or more grains that are larger than one or more grains of the polycrystalline material. The processed ribbon may include a large crystal material or a single crystal material.

A dense β″-alumina/zirconia composite solid electrolyte and process for fabrication are disclosed. The process allows fabrication at temperatures at or below 1600° C. The solid electrolytes include a dense composite matrix of β″-alumina and zirconia, and one or more transition metal oxides that aid the conversion and densification of precursor salts during sintering. The composite solid electrolytes find application in sodium energy storage devices and power-grid systems and devices for energy applications.

A method and system of extracting iron oxide from ore is provided, which may include adding a chelating agent to an iron ore to form an iron ore and chelating agent solution, heating the solution to reflux in water, and filtering the solution to yield an extraction residue and a chelated iron solution. The chelated iron solution may be treated with a potassium hydroxide and water solution to yield iron hydroxide.

A method and system of extracting iron oxide from ore is provided, which may include adding a chelating agent to an iron ore to form an iron ore and chelating agent solution, heating the solution to reflux in water, and filtering the solution to yield an extraction residue and a chelated iron solution. The chelated iron solution may be treated with a potassium hydroxide and water solution to yield iron hydroxide.

The present disclosure is directed to an alpha alumina powder having a specific surface area, a specific crystallite size, and a specific particle size distribution for use in abrasive polishes, and method of making such powder. The method of making the alpha alumina powder can include calcining an aluminum oxide precursor powder at a temperature of 800-1500° C. and milling the calcined powder to the specific particle size distribution. The alpha alumina powder disclosed herein can quickly enable high removal rate with undiminished aesthetic quality when used in abrasive polishes.

A wavelength conversion device of the present disclosure includes a substrate, a phosphor layer that has a matrix containing zinc oxide and phosphor particles embedded in the matrix and that is supported by the substrate, a dielectric layer disposed between the substrate and the phosphor layer, and a protective layer that is disposed between the phosphor layer and the dielectric layer and that has an isoelectric point equal to or larger than 7. A main surface of the substrate includes, for example, first and second regions. The phosphor layer covers, for example, only the first region out of the first and second regions.

A wavelength conversion device of the present disclosure includes a substrate, a phosphor layer that has a matrix containing zinc oxide and phosphor particles embedded in the matrix and that is supported by the substrate, a dielectric layer disposed between the substrate and the phosphor layer, and a protective layer that is disposed between the phosphor layer and the dielectric layer and that has an isoelectric point equal to or larger than 7. A main surface of the substrate includes, for example, first and second regions. The phosphor layer covers, for example, only the first region out of the first and second regions.