Atomic force microscope system with cantilever having unbiased spin valve magnetoresistive strain gauge
US5856617A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1997 |
| Grant date | Jan 5, 1999 |
| Priority date | — |
| Expiry date | Sep 2, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/873
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An atomic force microscope (AFM) uses a spin valve magnetoresistive strain gauge formed on the AFM cantilever to detect deflection of the cantilever. The spin valve strain gauge operates in the absence of an applied magnetic field. The spin valve strain gauge is formed on the AFM cantilever as a plurality of films, one of which is a free ferromagnetic layer that has nonzero magnetostriction and whose magnetic moment is free to rotate in the presence of an applied magnetic field. In the presence of an applied stress to the free ferromagnetic layer due to deflection of the cantilever, an angular displacement of the magnetic moment of the free ferromagnetic layer occurs, which results in a change in the electrical resistance of the spin valve strain gauge. Electrical resistance detection circuitry coupled to the spin valve strain gauge is used to determine cantilever deflection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.