Evidence of low-energy tunneling excitations in the high-T/sub c/ superconductor YBa/sub 2/Cu/sub 3/O/sub 7-//sub x/
We have measured the internal friction Q/sup -1/ and the Young's-modulus sound velocity v/sub E/ at 1 kHz for YBa/sub 2/Cu/sub 3/O/sub 7-//sub x/. Below 20 K the relatiave change in the sound velocity and the temperature dependence of the internal friction perfectly resemble the behavior obtained for Suprasil W. Below 1 K we observe a logarithmic temperature dependence for the sound velocity and between 1 and 5 K a well-defined plateau in the internal friction is obtained. We find quantitative agreement with the predictions of the standard tunneling model which is widely used to explain the low-temperature properties of amorphous materials. The implications of the existence of tunneling systems in these materials are discussed.
- Research Organization:
- Centro Atomico Bariloche, 8400 Bariloche, Argentina
- OSTI ID:
- 5741273
- Journal Information:
- Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 37:1; ISSN PRBMD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
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
FRICTION
INTERNAL FRICTION
MECHANICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
SOUND WAVES
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE
YOUNG MODULUS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES