University of Arkansas

University of Colorado

Superconducting Core Technologies, Inc.

Other

Alfred University

University Research Corporation

Allen M Hermann

Zhengzhi Sheng

Frank S Barnes

John C Price

Robert M Yandrofski

James F Scott

Xingwu Wang

Robert L Snyder

Hongmin Duan

Qamar A Shams

Q A Shams

J H Wang

Ali Naziripour

Timir Datta

Jemmy Hao

Gol A Naziripour

The present invention relates to a tuneable fringe effect capacitor for conducting radio frequency energy. The capacitor includes a thin film of ferroelectric material, a pair of films of a conductive material deposited on the ferroelectric film with a gap between the films, and a substrate for the ferroelectric material and the conductive films. The capacitance value across the gap is varied by applying a voltage to the ferroelectric material and thereby altering the dielectric constant of the ferroelectric material.

Tuneable microwave devices including fringe effect capacitor

A high temperature superconductor system is provided having the following formula: M-A-B-C-D-E, wherein, M is a metallic element. A is an element in Group 3A, B is an element in Group 2A, C is another element in Group 2A, D is an element in Group 1B, and E is an element in Group 6A. In an embodiment, the high temperature superconductor has the following formula: R-Tl-Sr-Ca-Cu-O (wherein R is chosen form the group consisting of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y). Processes for making these high temperature superconductors are also disclosed.

R-Tl-SR-CA-CU-O superconductors and processes for making same

The disclosure relates to ferroelectric and superconducting thin films used in combination to produce low-loss passive microwave and millimeter wave devices which are frequency tuneable. Various metal oxide superconducting and ferroelectric thin films can be deposited in numerous multilayer geometries via a variety of deposition techniques to produce devices which can manipulate microwave and millimeter wave signals through the application of voltage bias signals across the ferroelectric films. Numerous superconducting microwave and millimeter wave devices, including delay lines, phase shifters, resonators, oscillators, filters, electrically-small antennas, half-loop antennas, directional couplers, patch antennas, and various radiative gratings, are made frequency-tuneable by utilizing voltage-tuneable capacitor structures fabricated from voltage-biased ferroelectric thin films. Tuneable antenna arrays are also disclosed incorporating the combined superconducting and ferroelectric thin film structures and geometries which allow for electrical steering of beam patterns by the application of one or more voltage bias signals to ferroelectric thin film gratings.

Tuneable electric antenna apparatus including ferroelectric material

Tuneable microwave devices incorporating high temperature

A flux-trapped superconducting magnet which is formed of high transition temperature superconducting mixture doped with a magnetic material having a Curie temperature below the transition temperature of the superconducting mixture.

Flux-trapped superconducting magnets and method of manufacture

A process of making high temperature Tl-based superconductors. The process includes the steps of reacting solid Ba--Ca--Cu-oxides with Tl.sub.2 O.sub.3 vapor. The process allows high quality Tl-based superconductors to be easily fabricated.

Process for making Tl-Ba-Ca-Cu-O superconductors using thallium vapor

A method of forming thallium, barium, calcium, copper oxide films with smooth surfaces and chemical uniformity by sequentially depositing layers and annealing in the absence of a separate source of Tl.

Method of forming smooth, uniform thallium-based superconducting films

A high temperature superconducting system has the general composition Tl-R-X-Y, wherein: R is a Group 2A element; X is a Group 1B element; and Y is a Group 6A element. Preferably, the composition has the following formula Tl-Ba-Cu-O. The high temperature superconductor of the present invention has a transition temperature of about 90 K with the probability of one phase superconducting at a temperature perhaps as high as 270 K. Processes for making the high temperature superconductor are also provided.

High temperature superconductor system comprising Tl.sub.2 Ba.sub.2

A high temperature superconducting wire and an improved process of making the same wherein a metal wire chosen from the group consisting of: Y; Sm; Eu; Gd; Dy; Ho; Er; Tm; Yb; and Lu is oxidized and the oxidized metal wire is then coated with molten barium-copper-oxide. The process allows high-quality superconducting wire to be easily and continuously fabricated.

Process for making composite ceramic superconducting wires

A high temperature superconductor system having the nominal composition: Tl-Ba-Ce-Cu-O. The high temperature superconductor of the present invention has a transition temperature of about 90 K. Processes for making the high temperature superconductor are also provided.

90 K Tl-Ba-Ce-Cu-O superconductor and processes for making same

A high temperature superconductor having the formula Tl-Sr-Ca-Cu-O and a transition temperature about 70 K (with some evidence of a 100 K phase) is provided. Processes for making high temperature superconductors are also provided.

Tl-Sr-Ca-Cu-O superconductors

A new high temperature superconducting system with transition temperature above 120 K is disclosed. One superconductor in that system in a preferred embodiment comprises TlRBaCuO wherein R is chosen from Group 2A elements excluding Ba. In a preferred embodiment, the superconductor is TlCaBaCuO. In another preferred embodiment, the superconductor comprises TlSrCuO. Processes for making high temperature superconducting system are also disclosed.

Processes for making Tl-Ca-Ba-Cu-O, Tl-Sr-Ba-Cu-O and Tl-Sr-Cu-O

A process of making high temperature Tl-based superconductors is disclosed. The process includes the steps of reacting solid Ba-Ca-Cu-oxides with Tl.sub.2 O.sub.3 vapor. The process allows high quality Tl-based superconductors to be easily fabricated.

Preparation of superconducting Tl-Ba-Ca-Cu-O thin films by Tl.sub.2 O.sub.3

A high temperature superconducting system has the general composition Tl-R-X-Y, wherein: R is a Group 2A element; X is a group 1B element; and Y is a Group 6A element. Preferably, the composition has the following formula Tl-Ba-Cu-O. The high temperature superconductor of the present invention has a transition temperature of about 90 K with the probability of one phase superconducting at a temerature perhaps as high as 270 K. Processes for making the high temperature superconductor are also provided.

High temperature superconductor system having the formula Tl-Ba-Cu-O

A two-step process for the preparation of a thallium-containing superconductive film is described. In the first step of this process, an aerosol mist containing reactants necessary to produce a calcium/barium/strontium/copper precursor material is provided. This mist is subjected to radio-frequency radiation while in the plasma region, and it thereafter is deposited onto an electrically grounded substrate. In the second step of the process, the coated substrate is contacted with thallium-containing vapor.

Growing community of inventors

Fayetteville, AR, United States of America

Allen M Hermann