Fuji Electric Co., Ltd.

Fuji Electric Corporate Research and Developement Ltd.

Fuji Electronic Corporation, Ltd.

Kazuo Mukae

Koichi Tsuda

Ikuo Nagasawa

Satoshi Maruyama

Takashi Ishii

Toyoshige Sakaguchi

Hiroshi Kimura

Toshiyuki Matsui

Akihiko Ohi

Takeshi Suzuki

Masaharu Namba

Shigenori Takayasu

A superconducting transistor having a source region and a drain region are formed by a YBCO film on a barrier layer, which is composed of a PBCO film formed on an STO substrate. A gate electrode is disposed on the thinner wall at the back of the STO substrate. In a superconducting transistor so constructed the electric field created by the gate voltage works effectively at an interface with the barrier layer, more carriers can be drawn out relative to the applied gate voltage, and it becomes possible for a large superconduction current to flow.

Superconducting device structure with Pr-Ba-Cu-O barrier layer

A superconducting transistor with superior withstand voltage having source region and a drain region formed of oxide superconductors 3, a PrBa.sub.2 Cu.sub.3 O.sub.7-x layer 2 or an ScBa.sub.2 Cu.sub.3 O.sub.7-x layer 2 forming an intermediate region sandwiched by the source and drain regions. The regions are disposed on a substrate 1. An insulation layer 4 is disposed on the intermediate region. A transistor uses the intermediate region as an insulator when the gate is turned off, and as a superconductor when the gate is turned on.

Superconducting FET with Pr-Ba-Cu-O channel

A voltage-dependent nonlinear resistor from a sintered composition of zinc oxide (ZnO) as a chief component and the following auxiliary components: a rare earth element; cobalt (Co); at least one of magnesium (Mg) and calcium (Ca); at least one of potassium (K), cesium (Cs) and rubidium (Rb); chromium (Cr); boron (B); at least one of aluminum (Al), gallium (Ga) and indium (In); and at least one of antimony (Sb), niobium (Nb), tungsten (W), tantalum (Ta) and phosphorus (P). A voltage-dependent nonlinear resistor from a sintered composition of zinc oxide (ZnO) as a chief component and the following auxiliary components: praseodymium (Pr); cobalt (Co); potassium (K); chromium (Cr); and at least one of antimony (Sb), niobium (Nb) and tungsten (W).

Voltage-dependent nonlinear resistor

A method of producing a voltage nonlinear ZnO varistor in which seed grains of ZnO are produced by spray drying a slurry of ZnO particles and then sintering the dried slurry to form seed grains having a size of 10 to 100.mu.m. The seed grains are mixed with a ZnO powder of particles of much smaller size than the seed grains and a small amount of an auxiliary component. The mixture is then molded and sintered to form the varistor element to which electrodes are attached.

Method of producing a voltage-nonlinear resistor

A method of manufacturing a voltage nonlinear resistance element comprising the steps of providing a mixture of main component ZnO and auxiliary components of at least a rare earth element, Co and B in a mold, placing the mold in a sheath box having openings in the surfaces thereof, and baking the mold in the sheath box. The preferred ratio of the area of the openings in the sheath box to the total surface area of the sheath box is 10-90% to produce the voltage nonlinear resistance elements having favorable long wave tail surge withstanding data and an acceptable ratio of a voltage developed across the terminals of the element when a current of 1 mA flows in the element.

Method of manufacturing voltage nonlinear resistance elements

A nonlinear voltage resistor is formed by sintering a resistor body made from a powder predominantly comprising ZnO. The powder also includes a first element selected from the group of Li and Na and a second element selected from the group of Al, In, and Ga. The powder preferably includes 50 to 1,000 atomic ppm of the first element and a concentration of the second element sufficient to set the carrier concentration of the powder in the range of 5 atomic ppm to 120 atomic ppm.

Nonlinear voltage resistor

A zinc oxide voltage-nonlinear resistor is described. The resistor is produced by sintering a zinc oxide mixture containing 0.08 to 5.0 atomic % of at least one rare earth element, 0.1 to 10.0 atomic % of cobalt, 0.01 to 1.0 atomic % of at least one member of potassium, cesium, and rubidium, 0.01 to 1.0 atomic % of chromium, and 5.times.10.sup.-4 to 1.times.10.sup.-1 atomic % of boron, the balance being zinc oxide. This resistor has superior voltage nonlinearity and is greatly improved in the short duration discharge current withstand capability and the life performance under application of electricity.

Zinc oxide voltage nonlinear resistors

A voltage non-linear resistor in the form of a sintered body is disclosed. The sintered body is comprised of 0.08 to 5.0 atomic % of a rare earth element, 0.1. to 10 atomic % of cobalt, 5.times.10.sup.-4 to 1.times.10.sup.-1 atomic % of boron and an additional component which may be 0.01 to 5.0 atomic % of magnesium or calcium and/or 1.times.10.sup.-4 to 5.times.10.sup.-2 atomic % of aluminum, gallium or indium. The remainder of the sintered body is comprised of zinc oxide. The sintered body provides a small voltage non-linear resistor with high discharge current withstand capability and good life performance.

Zinc oxide non-linear resistor

A voltage-dependent nonlinear resistor containing ZnO as a main component and six auxiliary components, i.e., (1) a rare earth element; (2) Co; (3) at least one of Mg and Ca; (4) at least one of K, Rb and Cs, (5) as well as Cr; and (6) B which may be combined with at least one of Al, Ga and In. Alternatively, the auxiliary components may be (1) a rare earth element; (2) Co; (3) at least one of K, Rb and Cs; (4) Cr; (5) B; and (6) at least one of Al, Ga and In. The voltage-dependent nonlinear resistor of the present invention has high resistance to both long and short wave-tail surge currents and has an extended service life without sacrificing good nonlinearity.

Voltage non-linear resistance ceramics

Ceramics having nonlinear voltage characteristics in which (1) zinc oxide is used as a main component and (2) praseodymium, (3) one or more of magnesium or calcium, and (4) cobalt are added thereto as subcomponents, in elemental form or as a compound thereof, in an amount of from about 0.08 to about 10.0 atomic % for praseodymium, from about 0.08 to about 10.0 atomic % for the one or more of magnesium or calcium, and from about 0.1 to about 8.0 atomic % for the cobalt, each calculated as praseodymium, magnesium or calcium and cobalt.

Ceramics having nonlinear voltage characteristics

A ceramic having non-linear voltage characteristics, comprising the product obtained on mixing (a) zinc oxide, as a principal component, and (b) (1) cobalt and (2) one of neodymium, samarium or dysprosium, either in an elemental form or as a compound thereof, each in an amount of 0.1 to 10 atomic % for the cobalt, neodymium, samarium and dysprosium, calculated as cobalt, neodymium, samarium and dysprosium as subcomponents, and calcining the mixture at a temperature of from about 1150.degree. to about 1400.degree. C.

Ceramics having non-linear voltage characteristics and method of

Ceramics having nonlinear voltage characteristics comprising the product obtained on preparing a mixture of zinc oxide as a main component, and, as subcomponents, cobalt plus one of praseodymium or terbium, either in an elemental form or as a compound thereof, in an amount of from 0.1 to 8.0 atomic % for the cobalt, from 0.08 to 8.0 atomic % for the praseodymium and from 0.1 to 8.0 atomic % for the terbium, each calculated as cobalt, praseodymium and terbium, and calcining the mixture at a temperature in the range of from about 1150.degree. to about 1400.degree. C and a method for preparing the ceramics. An embodiment includes, as an additional subcomponent, lanthanum, either in an elemental form or as a compound in an amount of from 0.08 to 8.0 atomic %, calculated as lanthanum, with the zinc oxide, cobalt and praseodymium.

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Kanagawa, Japan

Kazuo Mukae