Complex transverse AC magneto-optic susceptometer for determination of volume and anisotropy field distribution in recording media
US7166997B2 · kind B2 · utility
8Cited by
9References
49Claims
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Key dates
| Filing date | Oct 6, 2003 |
| Grant date | Jan 23, 2007 |
| Priority date | — |
| Expiry date | Jun 10, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/0325
- WIPO fieldMeasurement
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.