Internal friction and ultrasonic attenuation related to carriers in high-[ital T][sub [ital c]] superconductors

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.49.1320· OSTI ID:5335196

Huang, Y N; Wang, Y N ^[1]; Zhao, Z X ^[2]

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1. National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210008 (China)
2. Institute of Physics, Academic Sinica, P.O. Box 603, Beijing 100080 (China)

For various samples of Bi-Sr-Ca-Cu-O (2:2:2:3 phase, 2:2:1:2 phase, and 2:2:2:3-2:2:1:2 mixed phases) and Tl-Ba-Ca-Cu-O (2:2:2:3 phase) with different [ital T][sub [ital c]], the internal friction ([ital Q][sup [minus]1]) in the kHz range reveals a plateau ([ital Q][sub [ital p]][sup [minus]1]) above [ital T][sub [ital c]] and drops drastically below [ital T][sub [ital c]] with the turning point at [ital T][sub [ital c]]. This kind of anomaly has not been observed for nonsuperconducting samples. The results of ultrasonic attenuation ([alpha]) in Tl-Ba-Ca-Cu-O (2:2:2:3) are similar to that of the internal friction mentioned above. Moreover, it is discovered that the [ital Q][sub [ital p]][sup [minus]1] is nearly proportional to Hall carrier density ([ital n][sub [ital H]]) for Y[sub 1[minus][ital x]]Pr[sub [ital x]]Ba[sub 2]Cu[sub 3]O and Gd[sub 1[minus][ital x]]Pr[sub [ital x]]Ba[sub 2]Cu[sub 3]O with various Pr content. These results indicate that the drastic drop of [ital Q][sup [minus]1] and [alpha] below [ital T][sub [ital c]] is caused by superconducting condensation. The energy dissipation ([ital Q][sub [ital p]][sup [minus]1] and [ital a][sub [ital p]]) related to carriers can be explained reasonably by using a coupling model of carriers with local dynamic distortion. Furthermore, by taking into account the smearing of the superconducting gap structure caused by the recombination of quasiparticles and by modifying the BCS relative jump rate as [ital S]([ital E],[ital E][prime],[Gamma])=Re[l brace]1[minus][Delta][sup 2]/[([ital E][minus][ital i][Gamma])([ital E][prime][minus][ital i][Gamma])][r brace], the calculated results of internal friction and ultrasonic attenuation below [ital T][sub [ital c]] agree fairly well with the experimental data.

• OSTI ID: 5335196
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 49:2; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATTENUATION
BCS THEORY
CARRIER DENSITY
DAMPING
ENERGY GAP
FRICTION
HIGH-TC SUPERCONDUCTORS
INTERNAL FRICTION
SOUND WAVES
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
ULTRASONIC WAVES