Alliedsignal Inc.

Superconductor Technologies Inc.

William L Olson

Jean Yamanis

Michael M Eddy

Timothy W James

Beili Li

Robert B Hammond

Keith R Karasek

McDonald Robinson

Jeffry Thurston Donner

William E Liss

Novel articles are provided of thin super-conductive thallium-based copper oxide layers on inorganic, usually crystalline substrates. Novel methods are provided for ease of producing such articles, particularly involving sol-gel techniques and laser ablation. The articles have a highly oriented superconductive thallium-based copper oxide film, particularly epitaxial, with high superconductive transition temperatures and desirable electrical properties. The subject articles find use in a wide variety of electronic applications, particularly in microwave and millimeter wave devices.

Epitaxial thin superconducting thallium-based copper oxide layers

Methods and reactors are described for the production of thallium cuprate based high temperature superconductor films on a variety of substrates. The reactors provide for low volume cavities, means for rapidly heating and cooling to and from a predetermined elevated temperature and control of the thallium oxide overpressure during the processing. Uniform high temperature superconducting films are obtained while inhibiting reaction between the substrate and superconducting film during the processing.

Controlled thallous oxide evaporation for thallium superconductor films

This invention relates to a process for the preparation of a crystalline compound having an empirical formula LaCr.sub.x A.sub.1-x O.sub.4 .multidot.yH.sub.2 O where A is a metal selected from the group consisting of Mg, Sr, Ca and Ba, x ranges from 0.99 to about 0.7 and y ranges from 0 to 0.15. The process comprises adding a solution of the appropriate metal salts to a solution of ammonium hydroxide thereby precipitating a hydroxide gel intermediate, which is dried and calcined in air to yield the resultant crystalline compound which has a huttonite structure. Additionally, this invention relates to a process for the preparation of a ceramic powder having the empirical formula LaCr.sub.x A.sub.1-x O.sub.3, where A is a metal selected from the group consisting of Mg, Sr, Ca and Ba and x ranges from 0.99 to about 0.7. Finally, a ceramic composition having the empirical formula LaCr.sub.x S.sub.1-x O.sub.4 .multidot.yH.sub.2 O having a huttonite structure is also disclosed.

Preparation of lanthanum chromite powders by sol-gel

An epitaxial thallium-based copper oxide superconducting film is formed on a crystalline substrate by metalorganic deposition which comprises forming a film of carboxylate soap solution on said substrate, prepyrolyzing said film at a temperature of 350.degree. C. or less and pyrolyzing said film at a temperature of 800.degree.900.degree. C. in the presence of oxygen and an overpressure of thallium for a sufficient time to produce said epitaxial superconducting film.

Metalorganic deposition method for forming epitaxial thallium-based

This invention relates to a process for the preparation of a crystalline compound having an empirical formula LaCr.sub.x A.sub.1-x O.sub.4.yH.sub.2 O where A is a metal selected from the group consisting of Mg, Sr, Ca and Ba, x ranges from 0.99 to about 0.7 and y ranges from 0 to 0.15. The process comprises adding a solution of the appropriate metal salts to a solution of ammonium hydroxide thereby precipitating a hydroxide gel intermediate, which is dried and calcined in air to yield the resultant crystalline compound which has a huttonite structure. Additionally, this invention relates to a process for the preparation of a ceramic powder having the empirical formula LaCr.sub.x A.sub.1-x O.sub.3, where A is a metal selected from the group consisting of Mg, Sr, Ca and Ba, and x ranges from 0.99 to about 0.7. Finally, a ceramic composition having the empirical formula LaCr.sub.x A.sub.1-x O.sub.4.yH.sub.2 O having a huttonite structure is also disclosed.

Preparation of lanthanum chromate powders by sol-gel

This invention relates to a method of coating fibers by contacting the fibers with an organochlorosilane, drying and heating the fibers at a temperature of about 300.degree. to 500.degree. C., thereby coating the fibers. The choice of organochlorosilane and atmosphere under which the heating takes place will determine the composition of the coating.

Method of coating silicon carbide fibers

This invention relates to a process for the preparation of a crystalline compound having an empirical formula LaCr.sub.x A.sub.1-x O.sub.4 yH.sub.2 O where A is a metal selected from the group consisting of Mg, Sr, Ca and Ba, x ranges from 0.99 to about 0.7 and y ranges from 0 to 0.15. The process comprises adding a solution of the appropriate metal salts to a solution of ammonium hydroxide thereby precipitating a hydroxide gel intermediate, which is dried and calcined in air to yield the resultant crystalline compound which has a huttonite structure. Additionally, this invention relates to a process for the preparation of a ceramic powder having the empirical formula LaCr.sub.x A.sub.1-x O.sub.3, where A is a metal selected from the group consisting of Mg, Sr, Ca and Ba, and x ranges from 0.99 to about 0.7. Finally, a ceramic composition having the empirical formula LaCr.sub.x A.sub.1-x O.sub.4 yH.sub.2 O having a huttonite structure is also disclosed.

Preparation of lanthanum chromate and lanthanum chromite powders by

Alumina fibers whose surface is coated with zirconia to retain their identity in an alumina matrix when the mixture is sintered at temperatures needed to form a fully dense ceramic. The resulting fully dense ceramic composite shows the beneficial effects of such reinforcing fibers by having increased crack toughness.

Alumina composite reinforced by zirconia-clad alumina fibers

This invention relates to a process for reproducibly forming monodisperse titania spheres by the hydrolysis of titanium alkoxides in the presence of an amine containing additive in such a way as to constrain the particle size within a narrow range.

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Solvang, CA, United States of America

William L Olson