The Pinning Process Of Gdba2cu3o7-X Films

We measured the pinning force density F(p) in high quality GdBa2Cu3O7-x films as a function of temperature ranging 63-78 K and magnetic field up to 7 T. The results indicate that the process of pinning of a-axis oriented platelets in GdBa2Cu3O7-x films can be successfully explained by a transition from individual pinning to group pinning. The anisotropic pinning possibly results from a two-dimensional pinning center, and flux-lattice melting for H parallel-to C below and for H perpendicular-to C at H(c2), and an anisotropic vortex lattice.