Levitation force and magnetic stiffness in bulk high-temperature superconductors

Journal Article · Tue May 01 04:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.344927· OSTI ID:6904622

Chang, P Z; Moon, F C ^[1]; Hull, J R; Mulcahy, T M ^[2]

---

1. Department of Mechanical Engineering Department of Aerospace Engineering, Cornell University, Ithaca, New York 14853 (USA)
2. Materials Division Components Technology Division, Argonne National Laboratory, Argonne, Illinois 60439 (USA)

Levitation forces between a small permanent magnet and a disk of bulk high-temperature superconductor at 77 K were measured as a function of vertical separation for disks of composition Y-Ba-Cu-O, Ag/Y-Ba-Cu-O, (Pb,Bi)-Sr-Ca-Cu-O, and Tl-Ba-Ca-Cu-O. The forces were highly hysteretic; however, for all samples, on the initial descent of the magnet toward the disk, the force was unique, independent of magnet speed, and varied approximately as the negative exponential of the separation distance. Magnetic stiffness, associated with minor hysteresis loops, was found to be approximately proportional to the levitation force, and nearly independent of magnet configuration and superconductor composition.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6904622
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 67:9; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
HYSTERESIS
LEVITATION
LOW TEMPERATURE
MAGNETS
OXIDES
OXYGEN COMPOUNDS
PERMANENT MAGNETS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES