Novel technique using magnetic field dependent phase detection for detection of superconductivity
US4851762A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1988 |
| Grant date | Jul 25, 1989 |
| Priority date | — |
| Expiry date | Aug 31, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S505/843
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to a method and apparatus to detect the superconductive state by measuring the change in the resistance of a sample. A dc magnetic field is imposed on the sample while the temperature is swept. The strength of the magnetic field is held below the critical value and is frequency modulated by the application of an ac field in such a way that total magnetic field is always positive. The resistance of the sample is measured incrementally as the temperature is swept and is phase detected at the modulation frequency. According to this embodiment, only magnetic field dependent changes demonstrating a precipitous drop in resistance identify a composition as superconductive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.