Preparation of finely divided hexagonal ferrite powder

US5051201A · kind A · utility

Assignee

• BASF SE

Inventors

• Michael Mueller · Dresden, DE
• Ekkehard Schwab · Neustadt, DE
• Volker Arndt · Frankenthal (Pfalz), DE

Key dates

• Filing date: Sep 11, 1990
• Grant date: Sep 24, 1991
• Expiry date: Sep 11, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/42
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Finely divided hexagonal ferrite powder is prepared by autoclave treatment of an aqueous alkaline suspension containing the ferrite-forming metal ions at from 250.degree. to 330.degree. C. and subsequent heating of the resulting material at not more than 900.degree. C., by a process in which the ferrite-forming metal ions are used in the form of salts melted in their water of crystallization.