The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 25, 1992
Filed:
Apr. 17, 1989
James L Woodhead, Banbury, GB;
Paul Groves, Charlbury, GB;
Alcan International Limited, Montreal, CA;
Abstract
The invention concerns sol-gel techniques for making PZT-type ceramics having a perovskite-type structure and ferrite ceramics having a spinel-type structure. Colloidal hydrated oxide sols are mixed with metal salt solutions in the required concentration and the mixed sols dehydrated to form homogeneous gels which are fired at 250.degree. C.-650.degree. C., pressed and sintered at 900.degree.-1300.degree. C. The resulting ceramics include PZT4, PZT5 and lithium ferrites. These have excellent homogeneity, small grain size, high density and improved electrical properties, particularly low dielectric loss, compared with known ceramics of similar composition.