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:
Jan. 23, 2007
Filed:
Oct. 06, 2003
Ganping Ju, Wexford, PA (US);
Roy W. Chantrell, Pittsburgh, PA (US);
Hong Zhou, Pittsburgh, PA (US);
Dieter K. Weller, Gibsonia, PA (US);
Ganping Ju, Wexford, PA (US);
Roy W. Chantrell, Pittsburgh, PA (US);
Hong Zhou, Pittsburgh, PA (US);
Dieter K. Weller, Gibsonia, PA (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
A method and apparatus for determining volume and anisotropy field distribution of thin film granular material includes the use of a magneto-optic probe, a lock-in amplifier, and a computer. The magneto-optic probe utilizes the Kerr effect in order to determine the transverse AC susceptibility of the sample. The Lock-in amplifier determines the complex parameters of the susceptibility as a function of the DC field and AC frequency. Separate distribution values of anisotropy field and grain volume can then be determined mathematically from the relationship of complex susceptibility parameters to the DC field strength.