Midwest Superconductivity, Inc.

The State University of New York

University of Kansas

Yi-Han Kao

Deborah D Chung

Ying Xin

Kai W Wong

Xin Fei

Kevin T Fredette

Liwei Song

Wangsong He

Michael S Lucas

High T.sub.c superconducting magnetic shields are provided, together with a method of fabricating such shields, wherein the shields exhibit very high critical applied magnetic field values of at least about 50 Gauss at 77 K. In fabrication procedures, a particulate superconducting ceramic oxide (24) (e.g., thallium 2223) is placed within an uniaxial die assembly (10) and subjected to compression while the die is heated via an external heating jacket (26). After formation of a self-sustaining body (24a), the die (10) is additionally heated via the jacket (26). External heating of the die (10) with the superconducting material therein reduces internal stresses within the shield body.

High T.sub.c superconductor magnetic shields and method of making same

A superconductive fullerene and a process for making such superconductive fullerene are provided. The process involves contacting a quantity of fullerene with the vapor of an interhalogen compound such as ICl. The halogen doped fullerenes exhibited a transition temperature above 60 K.

Inter-halogen-doped superconductive fullerenes

Composite bulk superconducting materials having desirable physical, measured transport current density and high T.sub.c superconducting characteristics are provided which comprise a first matrix of superconducting ceramic oxide crystalline grains with a second matrix of elemental metal (gold, silver, palladium and tin) situated within the interstices between the crystalline grains. Preferably, each matrix is a continuous phase within the composite material, with the ceramic oxide preferably being present at a level of at least about 80% by weight, whereas the elemental metal is present at a level of up to about 20% by weight. In fabrication procedures, a precursor superconducting ceramic oxide is first prepared and reduced to a fine powder size; this is mixed with powdered elemental metal, and the mixture is compressed using high compaction pressures on the order of 14 tons/cm.sup.2 or greater to form a body, which is then sintered to yield the composite. Particularly preferred composites include a mixed metallic matrix including respective quantities of tin and a noble metal.

Superconductors having continuous ceramic and elemental metal matrices

A superconductive fullerene and a process for making such superconductive fullerene are provided. The process involves contacting-a quantity of fullerene with the vapor of an interhalogen compound such as ICl. The halogen doped fullerenes exhibited a transition temperature above 60 K.

Halogen-doped superconductive fullerenes

A selectively controllable, direction-, amplitude- and/or frequency-specific superconducting shield (10) is provided which includes a multiply-connected superconducting shield (12) adapted to shield a zone (13) from external magnetic, electric and/or electromagnetic fields and signals. Controlled gating of the shield (12) is provided by means (16) serving to selectively lower the critical shielding current density of a portion (26) of the shield (12) to a level permitting entrance of external fields through the portion (26), while leaving the critical shielding current densities of other portions of the shield (12) at higher, field-shielding levels. The means (16) preferably includes respective, selectively energizable coil pairs (CP.sub.1, CP.sub.2 . . . CP.sub.n) disposed about the shield (12). A highly sensitive magnetic detector (30) would include the shielding device (10) as well as a SQUID assembly (18) situated within the zone (13) defined by shield (12). The detectors of the invention may be used in passive, gating-controlled arrays in order to improve signal discrimination and signal-to-noise characteristics of conventional arrays.

Growing community of inventors

Williamsville, NY, United States of America

Yi-Han Kao