Sumitomo Electric Industries, Limited

Agency of Industrial Science and Technology

Rikagaku Kenkyusho

Tatsuya Nishimoto

Eiji Kamijo

Matsuo Higuchi

Fumio Ono

Ikuji Uemura

Naoki Matsumoto

Kensaku Motoki

Takuji Okahisa

Koichi Okita

Masaaki Honda

Shohei Isomura

Yoji Kawami

Ryohei Nakane

Noboru Wakabayashi

Eiichi Torigai

Katsuhito Tani

A freestanding GaN single crystal substrate is made by the steps of preparing a (111) GaAs single crystal substrate, forming a mask having periodically arranged windows on the (111) GaAs substrate, making thin GaN buffer layers on the GaAs substrate in the windows of the mask, growing a GaN epitaxial layer on the buffer layers and the mask by an HVPE or an MOC, eliminating the GaAs substrate and the mask away and obtaining a freestanding GaN single crystal substrate. The GaN single crystal has a diameter larger than 20 mm and a thickness more than 0.07 mm, being freestanding and substantially distortion-free.

GaN single crystal substrate and method of producing same

The present invention relates to a method of hot rolling copper or copper alloys such as copper wires and coppr plates. The present invention has succeeded in remarkably prolonging useful life of the tools used for hot rolling, and improving the surface quality of the rolled products by replacing the conventional methods of hot rolling copper using tools made of cemented carbide, die steel, high-speed steel, etc. by a method using tolls made essentially of Si.sub.3 N.sub.4. Si.sub.3 N.sub.4 tools used in the present invention contain at least one kind of sintering aid selected from the group consisting of Al.sub.2 O.sub.3, AlN, MgO, Y.sub.2 O.sub.3 and ZrO.sub.2, have a sintering density of 90% or more, Rockwell hardness of 88 or more and an average particle diameter of 2.mu. or less, and contain .beta.-type Si.sub.3 N.sub.4 as a main ingredient.

Method of hot rolling copper

A novel method of hot rolling iron and iron alloy rods, using a hot rolling tool comprising .beta.-Si.sub.3 N.sub.4 and a sintering aid selected from the group consisting of Al.sub.2 O.sub.3, AlN, MgO, Y.sub.2 O.sub.3 and ZrO.sub.2, and having a sintered density of 90% or more, Rockwell hardness of 88 or more and a mean particle size of 2.mu. or less.

Method of hot rolling for iron and iron alloy rods

The invention relates to an aqueous electrolytic cathode and/or anode in which an aqueous solution of alkaline metal hydroxide is used or an active nickel or nickel alloy electrode having greater stability and smaller overvoltage under the condition of high current density for use in electrolysis of aqueous solution of alkaline metal halide, and the method for producing the same. Electrode material consisting of nickel or nickel alloy or electrode material of multiple layers comprising said electrode material coated with nickel or nickel alloy powder is forcibly subjected to oxidization and reduction treatments in repetition under a selected treatment temperature and atmosphere so that the surface area is expanded by the production of surface openings, thereby enabling to obtain an electrode having the said high properties.

Electrode and the method for producing the same

A catalyst for concentrating hydrogen isotopes for use in performing hydrogen isotopes exchange between gaseous hydrogen and liquid water, the catalyst comprising a support of porous polytetrafluoroethylene having a total specific surface area of 2 to 80 m.sup.2 /g as a result of mixing therewith 0.5 to 15% by weight of fluorocarbon or a porous styrene polymer or styrene/divinylbenzene copolymer having a specific surface area of at least 150 m.sup.2 /g, and deposited on the support particles of at least one element selected from Group VIII of the Periodic Table. A method for producing a support of porous polytetrafluoroethylene for such catalyst is also disclosed.

Catalyst for concentrating hydrogen isotopes and process for producing a

A method for producing a tubular multi-layered porous barrier comprising the step of depositing fine powder onto at least one of the inner and outer surfaces of a sintered tubular porous support member in a layer of uniform thickness to form a fine powder layer and pressurizing said powder layer against said support member to form a porous barrier layer on the support member.

Method for producing a tubular multi-layered porous barrier

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Itami, Japan

Tatsuya Nishimoto