Los Alamos National Security, LLC

University of California

Ut-battelle, Inc.

Jersey Nuclear-avco Isotopes, Inc.

Other

The United States of America As Represented by the United States

Paul N Arendt

Stephen R Foltyn

Quanxi Jia

James R Groves

Igor Olegovich Usov

Liliana Stan

Haiyan Wang

Yuntian Theodore Zhu

Terry G Holesinger

Mariappan Parans Paranthaman

Tolga Aytug

Vladimir Matias

Qingwen Li

Alicia Ayala

Srivatsan Sathyamurthy

Xiefei Zhang

Martin W Rupich

Qi Li

Leslie G Fritzemeier

Elliott D Thompson

Cornelis Leo Hans Thieme

Alp Tugrul Findikoglu

Michael A Bayne

Lawrence Eugene Bronisz

Edward J Siegal

D Wayne Cooke

Robert H Hammond

Lei Fu

Xin Di Wu

Vance I Valencia

Lester M Finch

Helmut Piel

Suresh Annavarapu

Steve R Foltyn

Raymond F DePaula

Marion L Scott

Xiefie Zhang

Ramond F DePaula

Woong Choi

Sascha Kreiskott

Lianxi Zheng

A spun fiber of carbon nanotubes is exposed to ion irradiation. The irradiation exposure increases the specific strength of the spun fiber.

Increasing the specific strength of spun carbon nanotube fibers

A structure for preparing an substantially aligned array of carbon nanotubes include a substrate having a first side and a second side, a buffer layer on the first side of the substrate, a catalyst on the buffer layer, and a plurality of channels through the structure for allowing a gaseous carbon source to enter the substrate at the second side and flow through the structure to the catalyst. After preparing the array, a fiber of carbon nanotubes may be spun from the array. Prior to spinning, the array can be immersed in a polymer solution. After spinning, the polymer can be cured.

Preparation of arrays of long carbon nanotubes using catalyst structure

An array of carbon nanotubes is prepared by exposing a catalyst structure to a carbon nanotube precursor. Embodiment catalyst structures include one or more trenches, channels, or a combination of trenches and channels. A system for preparing the array includes a heated surface for heating the catalyst structure and a cooling portion that cools gas above the catalyst structure. The system heats the catalyst structure so that the interaction between the precursor and the catalyst structure results in the formation of an array of carbon nanotubes on the catalyst structure, and cools the gas near the catalyst structure and also cools any carbon nanotubes that form on the catalyst structure to prevent or at least minimize the formation of amorphous carbon. Arrays thus formed may be used for spinning fibers of carbon nanotubes.

Preparation of array of long carbon nanotubes and fibers therefrom

A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

Carbon nanotube fiber spun from wetted ribbon

A superconducting article includes a substrate having an untextured metal surface; an untextured barrier layer of LaZrOor GdZrOsupported by and in contact with the surface of the substrate; a biaxially textured buffer layer supported by the untextured barrier layer; and a biaxially textured superconducting layer supported by the biaxially textured buffer layer. Moreover, a method of forming a buffer layer on a metal substrate includes the steps of: providing a substrate having an untextured metal surface; coating the surface of the substrate with a barrier layer precursor; converting the precursor to an untextured barrier layer; and depositing a biaxially textured buffer layer above and supported by the untextured barrier layer.

Chemical solution deposition method of fabricating highly aligned MgO templates

The present invention relates to a thin film structure based on an epitaxial (111)-oriented rare earth-Group IVB oxide on the cubic (001) MgO terminated surface and the ion-beam-assisted deposition ('IBAD') techniques that are amendable to be over coated by semiconductors with hexagonal crystal structures. The IBAD magnesium oxide ('MgO') technology, in conjunction with certain template materials, is used to fabricate the desired thin film array. Similarly, IBAD MgO with appropriate template layers can be used for semiconductors with cubic type crystal structures.

Wide band gap semiconductor templates

A composite structure including a base substrate and a layer of a mixture of strontium titanate and strontium ruthenate is provided. A superconducting article can include a composite structure including an outermost layer of magnesium oxide, a buffer layer of strontium titanate or a mixture of strontium titanate and strontium ruthenate and a top-layer of a superconducting material such as YBCO upon the buffer layer.

Buffer layer for thin film structures

Articles are provided including a base substrate having a layer of an IBAD oriented material thereon, and, a layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the layer of an IBAD oriented material. Such articles can further include thin films of high temperature superconductive oxides such as YBCO upon the layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates.

Coated conductors

Articles are provided including a base substrate having a layer of an oriented cubic oxide material with a rock-salt-like structure layer thereon, and, a layer of epitaxial titanium nitride upon the layer of an oriented cubic oxide material having a rock-salt-like structure. Such articles can further include thin films of high temperature superconductive oxides such as YBCO upon the layer of epitaxial titanium nitride or upon a intermediate buffer layer upon the layer of epitaxial titanium nitride.

Architecture for coated conductors

A template article including a base substrate including: (i) a base material selected from the group consisting of polycrystalline substrates and amorphous substrates, and (ii) at least one layer of a differing material upon the surface of the base material; and, a buffer material layer upon the base substrate, the buffer material layer characterized by: (a) low chemical reactivity with the base substrate, (b) stability at temperatures up to at least about 800&#xb0; C. under low vacuum conditions, and (c) a lattice crystal structure adapted for subsequent deposition of a semiconductor material; is provided, together with a semiconductor article including a base substrate including: (i) a base material selected from the group consisting of polycrystalline substrates and amorphous substrates, and (ii) at least one layer of a differing material upon the surface of the base material; and, a buffer material layer upon the base substrate, the buffer material layer characterized by: (a) low chemical reactivity with the base substrate, (b) stability at temperatures up to at least about 800&#xb0; C. under low vacuum conditions, and (c) a lattice crystal structure adapted for subsequent deposition of a semiconductor material, and, a top-layer of semiconductor material upon the buffer material layer.

Near single-crystalline, high-carrier-mobility silicon thin film on a polycrystalline/amorphous substrate

A superconducting tape having reduced AC losses. The tape has a high temperature superconductor layer that is segmented. Disruptive strips, formed in one of the tape substrate, a buffer layer, and the superconducting layer create parallel discontinuities in the superconducting layer that separate the current-carrying elements of the superconducting layer into strips or filament-like structures. Segmentation of the current-carrying elements has the effect of reducing AC current losses. Methods of making such a superconducting tape and reducing AC losses in such tapes are also disclosed.

Segmented superconducting tape having reduced AC losses and method of making

A method that combines alternate low/medium ion dose implantation with rapid thermal annealing at relatively low temperatures. At least one dopant is implanted in one of a single crystal and an epitaxial film of the wide band gap compound by a plurality of implantation cycles. The number of implantation cycles is sufficient to implant a predetermined concentration of the dopant in one of the single crystal and the epitaxial film. Each of the implantation cycles includes the steps of: implanting a portion of the predetermined concentration of the one dopant in one of the single crystal and the epitaxial film; annealing one of the single crystal and the epitaxial film and implanted portion at a predetermined temperature for a predetermined time to repair damage to one of the single crystal and the epitaxial film caused by implantation and activates the implanted dopant; and cooling the annealed single crystal and implanted portion to a temperature of less than about 100&#xb0; C. This combination produces high concentrations of dopants, while minimizing the defect concentration.

Method for implantation of high dopant concentrations in wide band gap materials

A continuous process of forming a highly smooth surface on a metallic tape by passing a metallic tape having an initial roughness through an acid bath contained within a polishing section of an electropolishing unit over a pre-selected period of time, and, passing a mean surface current density of at least 0.18 amperes per square centimeter through the metallic tape during the period of time the metallic tape is in the acid bath whereby the roughness of the metallic tape is reduced. Such a highly smooth metallic tape can serve as a base substrate in subsequent formation of a superconductive coated conductor.

High current density electropolishing in the preparation of highly smooth substrate tapes for coated conductors

Articles are provided including a base substrate having a layer of an oriented material thereon, and, a layer of hafnium oxide upon the layer of an oriented material. The layer of hafnium oxide can further include a secondary oxide such as cerium oxide, yttrium oxide, lanthanum oxide, scandium oxide, calcium oxide and magnesium oxide. Such articles can further include thin films of high temperature superconductive oxides such as YBCO upon the layer of hafnium oxide or layer of hafnium oxide and secondary oxide.

High rate buffer layer for IBAD MgO coated conductors

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Los Alamos, NM, United States of America

Paul N Arendt