Apparatus for the demonstration of superconductivity at liquid nitrogen temperature by means of Meissner effect
One property of superconductive materials, the exclusion of a magnetic field, or Meissner effect, can be observed with only a magnet and a refrigeration source. Levitation of a cooled pellet of superconducting material above a magnet or levitation of a magnet above the superconducting material is commonly used as a means of demonstrating the presence of a superconductor. If the applied magnetic field is strong enough relative to the amount of superconductive material present in the sample, levitation can be observed. However, if the fraction of superconductor in the pellet is not great enough to overcome the force of gravity, the repulsive force may not be apparent without sensitive equipment. If the material is a powder, a superconductor may be detected by sprinkling the powder into a container of liquid nitrogen with a magnet in or beneath it. The superconducting material avoids the region of high magnetic flux, leaving a bare spot. According to the authors, 2% of superconducting powder admixed with inert copper oxide can be detected in this way. This method requires the use of only simple, inexpensive equipment that, except for the liquid nitrogen, is likely to be available in most laboratories. It will by useful for the detection of superconductivity in known compounds.
- Research Organization:
- Engelhard Corp., East Newark, NJ (USA)
- OSTI ID:
- 6749233
- Journal Information:
- Anal. Chem.; (United States), Vol. 60:18
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BARIUM OXIDES
SUPERCONDUCTIVITY
COPPER OXIDES
YTTRIUM OXIDES
EXPERIMENTAL DATA
LOW TEMPERATURE
MAGNETIC FIELDS
MEASURING INSTRUMENTS
MEISSNER-OCHSENFELD EFFECT
POWDERS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
DATA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
INFORMATION
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties