Critical current anisotropy of BiSrCaCuO thin films under magnetic fields
Résumé
We report on the strong angular dependence under magnetic
field of the critical currents of c-axis oriented Bi2 Sr2CaCu2 0 8
thin films, measured as a function of the angle 9 between the c-axis
and the applied magnetic field (H :5:20 T). The curves J c (9) at a
given field H present a peaked maximum occurring when H is parallel to
the Cu02 planes (9=90°). At 9~90°. J c appears to depend only on the
perpendicular field component H~ (along the c axis). In particular at
4.2 K and for H~ >0.02 T, it is shown that Jc(H. 9) behaves as IHcosOrUwith 0.44 :5: u:5: 0.50.