The angular dependence of the critical current density of textured YBaCuO

Highly textured bulk YBaCuO samples consisting of dense highly oriented platelets were prepared by a liquid phase process. Critical current density measurements at 77 K and at 6 T were made as the angle between the transport current and the externally applied magnetic field was varied in the ab-plane. At all times, the c-axis was perpendicular to both the DC transport current and the external magnetic field. The critical current density values were found to achieve a maximum of 7000 A/cm/sup 2/ when the magnetic field was parallel to the transport current and a minimum of 2000 A/cm/sup 2/ when the magnetic field was close to an orientation perpendicular to the transport current, with one notable exception: a small increase to approximately 3000 A/cm/sup 2/ from the minimum value of 2000 A/cm/sup 2/ was observed when the magnetic field was perpendicular to the transport current. Ignoring this exception, the angular variation of critical current density is qualitatively consistent with the variation expected from the Lorentz force acting upon the vortices.<>