Ceramic cold conductor and method of producing the same

US4425556A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Leopold Hanke · Beyharting, DE
• Helmut Schmelz · Prien am Chiemsee, DE

Key dates

• Filing date: May 4, 1981
• Grant date: Jan 10, 1984
• Expiry date: May 4, 2001

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01B1/08
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

Ceramic cold conductors based on barium titanates having the general formula: EQU (Ba.sub.1-x M.sup.II)O.z(Ti.sub.1-y M.sup.IV y)O.sub.2 wherein M.sup.II is selected from the group consisting of Ca, Mg, Sr and Pb; M.sup.IV is selected from the group consisting of Sn and Zr; x and y are numerals, the sum of which does not exceed one and z is a numeral in the range of 1.005 to 1.05, and containing one or more different doping elements, one of which (antimony, bismuth, niobium, lanthanum, yttrium or rare earth metals) in the barium titanate crystal lattice exhibits a predominant donor property and another of which (chromium, cobalt, copper, iron, manganese, nickel or vanadium) exhibits a predominant acceptor property, are produced by converting a mixture of appropriate starting materials into a conversion product, reducing the particle size of such conversion product, forming a body from such particles, sintering such body and subjecting the sintered body to a cooling and holding phase in special atmospheres to attain a final product. The doping element exhibiting donor property is present at a total concentration of 0.35 to 5 atomic percent in a Perowskite lattice and a doping elemen…