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

CORREA, V.F.; HERBSOMMER, J.A.; KAUL, E.E.; DE LA CRUZ, F.; NIEVA, G.

PHYSICA C - SUPERCONDUTIVITY

ELSEVIER SCIENCE BV

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 Bi2Sr2CaCu2O8+delta The data cover the low temperature (T < 25K) and low held (H-a < 1000 Oe) region of the magnetic (H-a-T) phase diagram. In optimally doped as well as in overdoped samples a crossover to a O-dimensional pinning regime (Larkin length, L-C(C), shorter than the inter-plane CuO2 distance) is observed at a characteristic temperature Too 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 T-0D.