Vortex Depinning in YBa sub 2 Cu sub 3 O sub 7: Resistive Transition Identification of the Crossover from Flux-Creep to Flux-Flow Behavior.

Analysis of resistive transitions of YBa sub 2 Cu sub 3 O sub 7 crystals reveals a scaling behavior which identifies the vortex-depinning critical field H sub cp, hence the crossover in behavior from flux creep to flux flow. The inferred H sub cp for YBa sub 2 Cu sub 3 O sub 7 crystals closely approximates the magnitude and temperature dependence of H sub cp derived from penetration length measurements of thin films.