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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 2 Issue 2 (1998) pp 177-182
Anomalies of attenuation and phase velocity of surface acoustic waves in $\mathsf{YBa_{ 2}Cu_{ 3}O_{7-\delta}}$ thin films in the vicinity of $\mathsf{T_ c}$
M. Stenger (1), S. Baumhoff (1) (a), J.-Y. Prieur (1)(2), J. Joffrin (1), J.-P. Contour (3)
(1) Laboratoire de Physique des Solides, Université de Paris-Sud, 91405 Orsay Cedex, France
(2) Laboratoire LMDH, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05, France
(3) Unité Mixte de Physique CNRS/THOMSON, Domaine de Corbeville, 91404 Orsay Cedex, France
Received: 7 August 1997 / Revised: 7 November 1997 / Accepted: 17 November 1997
Abstract: We present measurements of the attenuation and phase velocity of surface acoustic waves in thin YBa2Cu3O$_{7-\delta}$ films as a function of temperature, in magnetic fields up to 3.6 T applied parallel to the c-axis of the films. We have observed anomalies in both, the attenuation and the phase velocity in the vicinity of the superconducting critical temperature which do not depend on the magnetic field. Possible origins of these anomalies, observed, to our knowledge, for the first time in YBa2Cu3O$_{7-\delta}$ thin films, are discussed and compared to bulk acoustic wave experiments. We present a kind of feedback technique for surface acoustic waves which improves the sensitivity of this type of measurement. The actual sensitivity limits are mentioned.
PACS. 62.40.+i Anelasticity, internal friction, stress relaxation, and mechanical resonances - 73.50.Rb Acoustoelectric and magnetoacoustic effects - 74.25.Ld Mechanical and acoustical properties, elasticity, and ultrasonic attenuation
(a) email: baumhoff@lps.u-psud.fr
Online publication: May 5, 1998
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