An alumina grain has a single-crystal structure and has an approximate regular octahedral stereoscopic morphology. Eight sides of the alumina grain belong to the {111} family of crystal planes of γ-state alumina, and the grain size is 5-100 μm. The alumina grain is unique in crystal plane exposure and distribution, simple and feasible in preparation, and low in cost, and has higher operability, and thus has good application prospect in the field of catalysis and adsorption.

A plate-like alumina particle containing a coloring component is provided. A plate-like alumina particle containing molybdenum, silicon, and a coloring component. A method for manufacturing the plate-like alumina particle, the method including the steps of mixing an aluminum compound containing an aluminum element, a molybdenum compound containing a molybdenum element, silicon or a silicon compound, and a coloring component so as to produce a mixture and calcining the resulting mixture.

A plate-like alumina particle containing a coloring component is provided. A plate-like alumina particle containing molybdenum, silicon, and a coloring component. A method for manufacturing the plate-like alumina particle, the method including the steps of mixing an aluminum compound containing an aluminum element, a molybdenum compound containing a molybdenum element, silicon or a silicon compound, and a coloring component so as to produce a mixture and calcining the resulting mixture.

A crucible device for growing crystals includes a container being arrangeable in a heating chamber of a heating apparatus, and a seed fixture element. The container includes a base section and the seed fixture element includes a seed surface which is configured for attaching a seed crystal. The seed fixture element is moveable coupled to the base section such that the distance between the seed surface and the base section is adjustable.

A crucible device for growing crystals includes a container being arrangeable in a heating chamber of a heating apparatus, and a seed fixture element. The container includes a base section and the seed fixture element includes a seed surface which is configured for attaching a seed crystal. The seed fixture element is moveable coupled to the base section such that the distance between the seed surface and the base section is adjustable.

The disclosure provides a film forming method that enables to obtain an epitaxial film with reduced defects such as dislocations due to a reduced facet growth industrially advantageously, even if the epitaxial film has a corundum structure. When forming an epitaxial film on a crystal-growth surface of a corundum-structured crystal substrate directly or via another layer, using the crystal substrate having an uneven portion on the crystal-growth surface of the crystal substrate, generating and floating atomized droplets by atomizing a raw material solution including a metal; carrying the floated atomized droplets onto a surface of the crystal substrate by using a carrier gas; and causing a thermal reaction of the atomized droplets in a condition of a supply rate limiting state.

The invention provides methodology for final finishing of hard surfaces such as diamond surfaces. In this method, a smooth pad having a surface roughness of about 0.2 nm to about 100 nm, having, for example a thickness ranging from about 0.02 mm to about 5 mm, and a Shore D hardness of 30 or higher, is utilized in conjunction with known polishing slurries to provide diamond surfaces having superior smooth finishes.

A method for manufacturing epitaxial films with multiple stress states, comprising steps of: providing a first single crystal substrate, and forming a sacrificial layer and a first epitaxial film on the first single crystal substrate, wherein the first epitaxial film is made of a first material;

removing the sacrificial layer to separate the first epitaxial film from the first single crystal substrate; transferring the first epitaxial film to a second single crystal substrate, wherein the second single crystal substrate is made of a second material, a partial surface of the second single crystal substrate being overlapped by the first epitaxial film; applying epitaxies onto the first epitaxial film and the second single crystal substrate to form a second epitaxial film on the first epitaxial film and the second single crystal substrate.

A method for manufacturing epitaxial films with multiple stress states, comprising steps of: providing a first single crystal substrate, and forming a sacrificial layer and a first epitaxial film on the first single crystal substrate, wherein the first epitaxial film is made of a first material;

removing the sacrificial layer to separate the first epitaxial film from the first single crystal substrate; transferring the first epitaxial film to a second single crystal substrate, wherein the second single crystal substrate is made of a second material, a partial surface of the second single crystal substrate being overlapped by the first epitaxial film; applying epitaxies onto the first epitaxial film and the second single crystal substrate to form a second epitaxial film on the first epitaxial film and the second single crystal substrate.

A method of producing a crystalline material is provided that may include providing a crystal growth apparatus comprising a chamber, a hot zone, and a muffle. The hot zone may be disposed within the chamber and include at least one heating system, at least one heat removal system, and a crucible containing feedstock. Additionally, the method may include providing a muffle that surrounds at least two sides of the crucible to ensure uniform temperature distribution through the feedstock during crystal growth to allow the crystalline material to be grown with a square or rectangular shaped cross section.