Amr A Adly

US Patent:

52647943, Nov 23, 1993

Filed:

Sep 21, 1992

Appl. No.:

7/947693

Inventors:

Edward R. Burke - Silver Spring MD
Isaak D. Mayergoyz - Rockville MD
Amr A. Adly - Hyattsville MD
Romel D. Gomez - Beltsville MD

Assignee:

The United States of America as represented by the Director, National
Security Agency - Washington DC

International Classification:

G01R 3300
G01R 3312

US Classification:

324260

Abstract:

The present invention discloses a method of measuring magnetic fields on magnetically recorded media. The method entails replacing the metal tip typically used with a scanning tunneling microscope with a flexible thin-film nickel of iron magnetic probe. The present invention describes a mathematical equation that relates probe position to magnetic field strength. In order to establish a tunneling current between the magnetic probe and the magnetically recorded media, any protective layer on the magnetically recorded media is removed. The magnetic probe and the magnetically recorded media may be coated with at least three-hundred angstroms of gold in order to reduce spurious probe deflections due to oxide growths on either the magnetic probe or the magnetically recorded media. The scanning tunneling microscope is designed to maintain a constant tunneling current between the probe and the item being scanned. The present invention uses the scanning tunneling microscope to scan the recording tracks of magnetically recorded media.