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:
Apr. 15, 1980
Filed:
Sep. 28, 1978
Richard F Reade, Corning, NY (US);
Corning Glass Works, Corning, NY (US);
Abstract
This invention is concerned with the production of transparent glass articles having compositions in the Li.sub.2 O and/or Na.sub.2 O-FeO-Al.sub.2 O.sub.3 -SiO.sub.2 field which additionally contain NiO and/or CoO. Upon exposure to a specifically-defined heat treatment in an oxidizing atmosphere, very fine-grained crystallites of NiFe.sub.2 O.sub.4, CoFe.sub.2 O.sub.4, or (Co,Ni)Fe.sub.2 O.sub.4 are formed spontaneously at the surface of the glass article to produce an integral surface layer thereon having a thickness of not more than about several thousand angstroms. These ferrite surfaces can be magnetized in a strong magnetic field and are relatively easily demagnetized. Such capabilities recommend these surface-crystallized glasses for applications in the storing, recording, retrieving, and erasing of information.