Onset of the 0-dimensional vortex pinning behavior in the optimally doped and overdiped Bi2Sr2CaCu2O8+delta system

CORREA, VICTOR F; HERBSOMMER, J. A.; KAUL, ENRIQUE E.; NIEVA, GLADYS L.

PHYSICA C - SUPERCONDUTIVITY

North-Holand Elsevier

Lugar: Amsterdam; Año: 2000 vol. 341 p. 1285 - 1286

0921-4534

We report results of transverse AC magnetic permeability in the linear regime and DC magnetization loops for optimally doped and oxygen overdoped samples of BixSr2CaCu208+delta. The data cover the low temperature (T < 25K) and low field (Ha < 1000 Oe) region of the magnetic (Ha-T) phase diagram.In optimally doped as well as in overdoped samples a crossover to a 0-dimensional pinning regime (Larkin length, L_c^c , shorter than the inter-plane CuO2 distance) is observed at a characteristic temperature T_0D for all investigated fields.The order-disorder transition, identified by the second peak in magnetization and a non monotonous field dependence of the AC penetration depth, is quenched below TOD