Electricity: measuring and testing – Magnetic – Magnetic field detection devices
Patent
1992-09-21
1993-11-23
Snow, Walter E.
Electricity: measuring and testing
Magnetic
Magnetic field detection devices
324212, G01R 3300, G01R 3312
Patent
active
052647943
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. Any change in the magnetic field of the magnetically recorded media will cause a change in the tunneling current. The microscope will change the position of the probe in order to maintain a constant tunneling current. These changes in position are recorded as an image. A mathematical equation that relates probe position to magnetic field strength is then used to extract the magnetic fields of the magnetically recorded media from the recorded image of probe positions.
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Adly Amr A.
Burke Edward R.
Gomez Romel D.
Mayergoyz Isaak D.
Maser Thomas O.
Morelli Robert D.
Snow Walter E.
The United States of America as represented by the Director, Nat
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