Internal friction due to oxygen relaxation in superconducting YBa sub 2 Cu sub 3 O sub 7 minus. delta. above T sub c

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Journal of Materials Research; (USA)

DOI:https://doi.org/10.1557/JMR.1991.0232· OSTI ID:6194169

Cost, J R ^[1]; Stanley, J T ^[2]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico (US)
2. Arizona State University, Tempe, Arizona (US)

YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} has an internal friction peak near 210 {degree}C measured at 1.18 Hz. The shift in the temperature of this peak with frequency as measured with different internal friction techniques indicates that the relaxation process has an average activation energy of 1.14{plus minus}0.05 eV and a pre-exponential factor, {tau}{sub 0}=1.5{times}10{sup {minus}13} s (log {tau}{sub 0}={minus}12.82{plus minus}0.23). The peak height decreases during annealing at above 375 {degree}C in helium and increases when annealed in oxygen. The mechanism for the relaxation is believed to be the stress-induced motion of oxygen atoms in the Cu--O plane. Detailed analysis shows that the internal friction peak is determined by a spectrum of activation energies; this spectrum is a symmetrical single peak 0.12 eV wide at half-height. Models for the relaxation are considered and the resulting diffusivities are compared to tracer diffusion results.

• OSTI ID: 6194169
• Journal Information: Journal of Materials Research; (USA), Journal Name: Journal of Materials Research; (USA) Vol. 6:2; ISSN JMREE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
DIFFUSION
ELEMENTS
FREQUENCY RANGE
FRICTION
HIGH TEMPERATURE
HZ RANGE
INTERNAL FRICTION
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PENDULUMS
RELAXATION
STRESSES
TORSION
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES