Anisotropic Vortex Dynamics Related to Screening Currents and Microwave Currents under Magnetic Fields on High TC Superconductors

摘要

Modulated microwave absorption (MA) was measured under magnetic field sweeping at liquid nitrogen temperature on superconducting c-oriented and a-oriented YBCO thin films for various filed configurations. The both samples show strong low-field MA peaks resulted from the surface Meissner current. The MAs for the perpendicular field to the superconducting plane increase with increasing the sweep rate,indicating the stronger transient screening current due to viscous vortex motion. Anisotropic vortex dynamics were clarified on the a-YBCO.