Lucent Technologies Inc.

At+t Corp.

James Joseph Krajewski

Robert J Cava

William Frederick Peck

A novel intermetallic superconductor with surprisingly high transition temperature is disclosed. The material comprises B and C, and can form a bulk superconductor. Exemplary of the novel superconductors is material of nominal composition YPd.sub.5 B.sub.3 C.sub.x, with x chosen such that the C:B ratio is in the range 0.05-2. An exemplary bulk sample of such composition has T, (onset) of 22.5 K, with more than 15 volume % of the sample being superconducting.

Article comprising an intermetallic superconductor material

Dielectric materials comprising Ca.sub.5 R.sub.2 XO.sub.12 in which R is either Nb or Ta and X is selected from Ti and Ti.sub.1-x Zr.sub.x, have high dielectric constants (Ks), relatively low dielectric losses (Q), and low TCKs. The dielectric properties are affected by processing conditions, which for the both the niobate and tantalate embodiments preferably involve sintering and re-firing dielectric pellets at temperatures of 1400.degree. C. and above. The dielectric materials are particularly useful for microwave communications applications.

Low temperature coefficient dielectric materials and devices comprising

A novel intermetallic superconductor with surprisingly high transition temperature is disclosed. The material comprises B and C, and can form a bulk superconductor. Exemplary of the novel superconductors is material of nominal composition YPd.sub.5 B.sub.3 C.sub.x, with x chosen such that the C:B ratio is in the range 0.05-2. An exemplary bulk sample of such composition has T.sub.c (onset) of 22.5 K, with more than 15 volume % of the sample being superconducting.

Article comprising an intermetalllic superconductor material

Dielectric materials comprising Ca.sub.2 Ta.sub.2-x Nb.sub.x O.sub.7 have high dielectric constants (Ks) and relatively low temperature coefficients of dielectric constants (TCKs). Preferably, in this composition 0.20.ltoreq.x.ltoreq.1.20 and more preferably 0.32.ltoreq.x.ltoreq.0.40, and particularly preferred is the composite where x is 0.36. With a preferred embodiment where x is about 0.36, the dielectric constant is near 30 and the TCK is about 2 ppm/.degree.C., and the Q of the polycrystalline ceramic at 1 MHz is approximately 5000. The dielectric materials are particularly useful in microwave communications applications

Low temperature coefficient dielectric material comprising binary

The temperature dependent dielectric constants in the vicinity of room temperature have been measured for bulk ceramics which are phase-mixtures of Pb.sub.2 (Nb,Mg,Ti).sub.2 O.sub.6+x pyrochlores and Pb(Nb,Mg,Ti)O.sub.3 perovskites. A band of compositions has been found in which the negative temperature coefficient of dielectric constant for the pyrochlore is very closely compensated by the positive temperature coefficient of dielectric constant of the perovskite. These compositions have dielectric constants near 200, with Q's near 200 at 1 MHz, making them an intermediate family of dielectrics between the much studied high dielectric constant low Q Barium-Strontium Titanates and low dielectric constant high Q Barium-Lanthanide Titanates.

Pyrochlore based oxides with high dielectric constant and low

A decrease in the temperature coefficient of the dielectric constant (TCK) for polycrystalline ceramics of Barium Strontium Titanate (BST) through admixture with tetragonal bronze type Barium Strontium Niobate (BSN) has been found. For Ba.sub.0.5 Sr.sub.0.5 TiO.sub.3 ceramics, a 10% admixture of BSN decreases TCK by a factor of 2.5 at 10 MHz, with negligible degradation of the dielectric loss. A 37.5% admixture of BSN decreases TCK by a factor of more than 100. Dielectric constants for the mixtures are in the range of 200-500.

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Raritan, NJ, United States of America

James Joseph Krajewski