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. 27, 1990
Filed:
May. 04, 1987
Albert Huizing, Eindhoven, NL;
Cornelis P Zegers, Eindhoven, NL;
Johannen J Brondijk, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
The invention relates to a magnetic material for use in the magnetic recording and playback of information, which material consists of ferrite particles having the composition A.sub.1-y Zn.sub.y Fe.sub.2 O.sub.4, wherein A is one or more bivalent metal ions, which material is suitable for use in a recording medium having a high information density in that the magnetic material comprises monodisperse ferrite particles having an average particle size between 5 and 250 nm, preferably between 10 and 50 nm, and in that y is between 0.05 and 0.35. The magnetic material preferably is Co-Zn-ferrite. The material is manufactured by coprecipitation of a mixture of hydroxides succeeded by recrystallization at elevated temperature and pressure.