Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. IV France 06 (1996) C8-461-C8-464
Angular Dependence of Ultrasonic Attenuation at Hcl in YBa2Cu3O7 Single CrystalC. Hucho and M. Levy
University of Wisconsin, Milwaukee, Physics Department, Milwaukee, WI 53201, U.S.A.
The resistive behavior of type-II superconductors in the superconducting state is largely influenced by the materials' ability to pin magnetic flux lines. While an externally applied magnetic field leads to an ordered flux-lattice in defect-free superconductors, spatial variations in the superconducting order parameter tend to deform the vortex system. This has immediate implications for the temperatureand field-dependence of the critical current density. Simple estimates of the balance between the intervortex interaction and the vortexpinsite interaction dow for qualitative predictions of the temperature- and field-dependent resistive behavior of type-II superconductors. A low fiequency ultrasonic technique was developed, which was used to study the viscous properties of the vortex system.
© EDP Sciences 1996