On the rf surface resistance of the perovskite superconductors at 3 GHz
The rf surface resistance is measured for Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/ samples fabricated in different laboratories by exposing them to the rf field of a niobium cavity at 3 GHz in a temperature range from 4.2 to 300 K. The rf surface resistance of the best sample decreases sharply at the transition temperature from typically 0.2 ..cap omega.. at 100 K by more than two orders of magnitude. The residual losses measured at 4.2 K in the superconducting host cavity are strongly dependent on the purity of the sample. The observed dependence of the residual losses on the rf field level is attributed to the granular structure of the superconductor. Rf magnetic fields of up to 1800 A/m have been achieved in pulsed operation. This field corresponds to a surface current density of 1.3 . 10/sup 6/ A/cm/sup 2/. The low residual losses indicate that less than 1% of the conduction electrons of the perovskite superconductors remain unpaired.
- Research Organization:
- Los Alamos National Lab., NM (USA); Wuppertal Univ. (Gesamthochschule) (Germany, F.R.). Fachbereich Physik der Bergischen
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6058016
- Report Number(s):
- LA-UR-87-2537; CONF-870790-1; ON: DE87013170
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360104 -- Metals & Alloys-- Physical Properties
656100* -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MEISSNER-OCHSENFELD EFFECT
PHYSICAL PROPERTIES
RF SYSTEMS
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS