William R Peck

US Patent:

56584857, Aug 19, 1997

Filed:

Oct 3, 1995

Appl. No.:

8/538318

Inventors:

Robert Joseph Cava - Bridgewater NJ
James Joseph Krajewski - Raritan NJ
William Frederick Peck - Bridgewater NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

C04B 3546

US Classification:

252 629

Abstract:

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.

US Patent:

55523552, Sep 3, 1996

Filed:

Oct 3, 1995

Appl. No.:

8/538317

Inventors:

Robert J. Cava - Bridgewater NJ
James J. Krajewski - Raritan NJ
William F. Peck - Bridgewater NJ

Assignee:

AT&T Corp. - Murray Hill NJ

International Classification:

C04B 3546

US Classification:

501137

Abstract:

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. 5 Sr. sub. 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.