DISSIPATION ANISOTROPY OF HIGHLY C-AXIS-ORIENTED (BI,PB)(2)SR2CA2CU3OX SILVER-SHEATHED TAPES

Dissipation anisotropy of a highly c-axis-oriented (Bi,Pb)(2)Sr2Ca2Cu3 Ox, silver-sheathed tape in the vicinity of T-c(T/T-c>0.9) has been in vestigated by measuring the dependence of the magnetoresistance on the applied field, the temperature and the angle (theta) between the magn etic field direction and the tape surface. The results show that the d issipation anisotropy increases with the increase of the field and the temperature. It is found that the dissipation is only related to the magnetic field component perpendicular to the tape surface (c-axis com ponent), i.e., R(H,theta)=R(H sin theta). The experimental results can be accounted for in terms of the easy motion of two-dimensional (2D) pancake vortices along the CuO2 planes. (C) 1997 American Institute of Physics.