Extraordinary magnetoresistance at room temperature in inhomogeneous narrow-gap semiconductors
US6707122B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 2000 |
| Grant date | Mar 16, 2004 |
| Priority date | — |
| Expiry date | Oct 26, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12937
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A symmetric van der Pauw disk of homogeneous nonmagnetic semiconductor material, such as indium antimonide, with an embedded concentric conducting material inhomogeneity, such as gold, exhits room temperature geometric extraordinary magnetoresistance (EMR) as high as 100%, 9,100% and 750,000% at magnetic fields of 0.05, 0.25 and 4.0 Tesla, respectively. Moreover, for inhomogeneities of sufficiently large cross section relative to that of the surrounding semiconductor material, the resistance of the disk is field-independent up to an onset field above which the resistance increases rapidly. These results can be understood in terms of the field-dependent deflection of current around the inhomogeneity. The EMR exhibited by a composite van der Pauw sensor comprising a semiconductor having an embedded metallic inhomogeneity or internal shunt can be obtained from electrically equivalent externally shunted structures, such as rectangular plates including an external conductive shunt element which is simple to manufacture in the mesoscopic sizes required for important magnetic sensor applications. For example, a bilinear conformal mapping is used to transform a circular composite van der P…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.