Patent · US Expired

Manufacture of .gamma.-iron(III) oxide

US4052326A · kind A · utility

8Cited by

2References

4Claims

0Family size

Assignee

BASF SE

Inventors

Eduard Schoenafinger
Bernd Leutner · Bischofswerda, DE

Key dates

Filing date	Aug 30, 1976
Grant date	Oct 4, 1977
Priority date	—
Expiry date	Aug 30, 1996

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01P2004/10
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

A process for the manufacture of acicular .gamma.-iron(III) oxide of improved crystallinity and high coercive force by heating goethite or acicular alpha-iron(III) oxide particles at temperatures of from 500.degree. to 800.degree. C, reduction of the resulting product at temperatures of from 280.degree. to 600.degree. C and subsequent oxidation of the magnetite to .gamma.-iron(III) oxide of improved crystallinity and high coercive force.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.