Bulk-wave characterization of high-T(c) superconductors. Annual report, 1 November 1988-1 November 1989
The objective of this research is to characterize high-T(c) superconductors with ultrasonic waves. A peak in ultrasonic attenuation has been observed at the superconducting phase transition of the thallium superconducting compound with a T(c) = 103 K. The position of this peak is independent of frequency and therefore should not be produced by a relaxation mechanism. It may be produced by interactions with fluctuations associated with the superconducting phase transition. The magnitude of the peak decreases in magnetic fields up to 6 Tesla. This appears to be the first time that an attenuation effect has been observed which is directly associated with the superconducting state of a high-T(c) superconductor. Shear waves propagating parallel to the Copper Oxide planes and polarized in the CuO planes of a sinter forged YBa{sub 2}Cu{sub 3}O{sub 7} sample exhibit only one maximum in attenuation at around 180 K. Velocity measurements in the copper free high-T(c) superconductors Ba(1-x)K(x)BiO{sub 3} show a definite change in slope at the phase transition. Measurements in the heavy fermion superconductor UPt(3) show a 40 ppm change in velocity around 4.5 K, its antiferromagnetic phase transition temperature.
- Research Organization:
- Wisconsin Univ., Milwaukee, WI (USA). Dept. of Physics
- OSTI ID:
- 7072886
- Report Number(s):
- AD-A-214030/9/XAB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ACOUSTIC TESTING
ALKALINE EARTH METAL COMPOUNDS
ANTIFERROMAGNETISM
ATTENUATION
BARIUM COMPOUNDS
BISMUTH COMPOUNDS
BISMUTH OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
CUPRATES
DOCUMENT TYPES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
MAGNETIC FIELDS
MAGNETISM
MATERIALS TESTING
MECHANICAL PROPERTIES
NONDESTRUCTIVE TESTING
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PROGRESS REPORT
RELAXATION
SHEAR PROPERTIES
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TESTING
THALLIUM COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
ULTRASONIC TESTING
VELOCITY
WAVE PROPAGATION
YTTRIUM COMPOUNDS