Sumitomo Electric Industries, Limited

Other

Sony Corporation

Nobuhiro Saga

Kenichi Sato

Kazuya Ohmatsu

Jun Fujikami

Shuji Hahakura

Takashi Kyono

Koji Katayama

Kazuhiko Hayashi

Shinji Tokuyama

Kazuhide Sumiyoshi

Masaki Ueno

Yusuke Yoshizumi

Masahiro Adachi

Yohei Enya

Takamichi Sumitomo

Naoki Ayai

Tatsushi Hamaguchi

Katsunori Yanashima

Takatoshi Ikegami

Hideo Ishii

Shimpei Takagi

Shoichi Honjo

Yoshihiro Iwata

In a group III nitride semiconductor device according to one aspect of the present invention, in a p-type group III nitride semiconductor region formed on a semi-polar plane substrate, the concentration of hydrogen (H) contained in the p-type group III nitride semiconductor region is 25% or less of the concentration of a p-type dopant therein, and the concentration of oxygen contained in the p-type group III nitride semiconductor region is 5&#xd7;10atoms/cmor lower, and an angle between a normal axis of a primary surface of the semi-polar plane substrate and a c-axis of the semi-polar plane substrate is not lower than 45 degrees and not higher than 80 degrees or not lower than 100 degrees and not higher than 135 degrees in a waveguide axis direction of the group III nitride semiconductor device.

Group III nitride semiconductor device, and method for fabricating group III nitride semiconductor device

A III-nitride semiconductor laser device is provided with a laser structure and an electrode. The laser structure includes a support base which includes a hexagonal III-nitride semiconductor and a semipolar primary surface, and a semiconductor region provided on the semipolar primary surface. The electrode is provided on the semiconductor region. The semiconductor region includes a first cladding layer of a first conductivity type GaN-based semiconductor, a second cladding layer of a second conductivity type GaN-based semiconductor, and an active layer provided between the first cladding layer and the second cladding layer.

Group-III nitride semiconductor laser device, method of fabricating group-III nitride semiconductor laser device, and epitaxial substrate

Provided are an oxide superconducting wire which maintains a high critical current density and has a small current drift with small ac loss when the same carries an alternating current and a method of preparing the same, and a cable conductor which is formed by assembling such oxide superconducting wires. The oxide superconducting wire is a flat-molded stranded wire which is formed by twisting a plurality of metal-coated strands consisting of an oxide superconductor, and is characterized in that the flat-molded stranded wire has a rectangular sectional shape, and a section of each strand forming the flat-molded stranded wire has an aspect ratio (W1/T1) of at least 2. The method of preparing this oxide superconducting wire comprises the steps of preparing a stranded wire by twisting a plurality of strands, each of which is formed by metal-coating an oxide superconductor or raw material powder therefor, flat-molding the prepared stranded wire, and repeating rolling and a heat treatment of at least 800&deg; C. on the flat molded stranded wire a plurality of times.

Oxide superconducting wire

An oxide superconducting wire includes oxide superconducting filaments , a matrix , a covering layer , and an insulating layer . The matrix is placed so as to enclose the oxide superconducting filaments and is made of silver. The covering layer is placed so as to enclose the matrix , contains silver and manganese, and has a thickness of 10 &mgr;m to 50 &mgr;m. The insulating layer is placed so as to enclose the covering layer

Oxide superconducting wire having insulating coat and production method thereof

The present invention relates to an oxide superconducting wire. The wire has a filament made essentially of an oxide superconductor, and a stabilizing metal covering the oxide superconductor. The stabilizing metal includes a silver alloy having at least either higher mechanical strength or higher specific electrical resistance than that of silver. In one embodiment, the stabilizing metal further includes a first portion directly covering the oxide superconductor and a second portion covering the first portion. The first portion is adapted to prevent the component of the second portion from diffusing into and reacting with the oxide superconductor. The first and second portions have different materials, and the first portion is made essentially of an Ag&mdash;Sb alloy. In another embodiment, the stabilizing metal further has a first portion directly covering the oxide superconductor, a second portion covering the first portion and a third portion covering the second portion. The first portion is made essentially of silver or Ag&mdash;Sb alloy. The second portion is made essentially of silver or Ag&mdash;Sb alloy. The third portion has a different material with respect to the second portion.

Oxide superconducting wire with stabilizing metal have none noble component

Method of preparing oxide superconductive wire

An oxide superconducting stranded wire having inter-strand insulation and high critical current is provided. A wire including an oxide superconducting material and a matrix covering the material and consisting essentially of silver or a silver alloy is coated with a paint containing, as a main component, an organometallic polymer such as a silicone polymer or aluminum primary phosphorus in a paint reservoir, and the paint is baked in a baking furnace via a drying furnace. A plurality of such wires with the baked paint are twined into a stranded wire, which is then heated up to a temperature necessary for sintering the oxide superconducting material. The stranded wire thus obtained through the step of sintering may have high critical current. A heat-resisting insulating coating layer may be formed by baking the paint.

Methods of manufacturing oxide superconducting stranded wire and oxide superconducting cable conductor, and coated wire, stranded wire and cable conductor

An oxide superconducting wire having a circular or substantially circular sectional shape and exhibiting a high critical current density comparable to that of a tape-shaped wire is provided. The oxide superconducting wire consists of a plurality of filaments extending along the longitudinal direction of the wire in the form of ribbons, and a stabilizer matrix covering the filaments. The aspect ratio of the width to the thickness of each filament is 4 to 40, and the thickness of each filament is 5 to 50 &mgr;m. A section of the wire is in a circular or substantially circular shape. The wire exhibits a critical current density of at least 2000 A/cm,at a temperature of 77 K with no application of a magnetic field. It is preferable that the plurality of filaments are substantially rotation-symmetrically arranged with respect to the center of the wire. It is also preferable that a hexagonal-prismatic stabilizing matrix is provided at the center of the wire and the plurality of filaments covered with the stabilizer matrix are arranged on each side surface thereof in a layered manner. A flat stranded wire having low ac loss can be formed by such wires.

Method of preparing oxide superconducting wire

An oxide superconducting wire having a circular or substantially circular sectional shape and exhibiting a high critical current density comparable to that of a tape-shaped wire is provided. The oxide superconducting wire consists of a plurality of filaments extending along the longitudinal direction of the wire in the form of ribbons, and a stabilizer matrix covering the filaments. The aspect ratio of the width to the thickness of each filament is 4 to 40, and the thickness of each filament is 5 to 50 .mu.m. A section of the wire is in a circular or substantially circular shape. The wire exhibits a critical current density of at least 2000 A/cm.sup.2 at a temperature of 77 K with no application of a magnetic field.

Multifilamentary oxide superconducting wires

Growing community of inventors

Osaka, Japan

Nobuhiro Saga