Method of making porous ceramics of a Pb (Zr.sub.x Ti.sub.1-x) O.sub.3 compound

US5958815A · kind A · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Peer Loebmann · Gerbrunn, DE
• Walther Glaubitt · Würzburg, DE
• Jochen Fricke · Würzburg, DE

Key dates

• Filing date: May 21, 1997
• Grant date: Sep 28, 1999
• Expiry date: May 21, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B35/624
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A method of making porous ceramics of lead titanate (PT) or lead zirconate PZT) of a Pb(Zr.sub.x Ti.sub.1-x) O.sub.3 compound from a gel made by mixing at least 2.5 equivalents of water based on the compound with a solution prepared from a polar solvent having complexing and chelating properties, one or more Pb(II) and PB(IV) carboxylates and at least one compound including titanium and zirconium of the general formula M(OR).sub.4 where M is titanium or zirconium and R is similar or different groups representing at least one of a straight chain, cross-linked and cyclic alkyl and alkenyl group with 1 to 10 carbon atoms, aging the resulting gel beyond its gel point, replacing the solvent in the pores of the gel by a chelating solvent, drying the resulting gel under supercritical conditions and tempering the resulting aerogel.