Local voltage-current characteristics in high superconductors

Local electric field versus current density (Formula presented) curves were measured in (Formula presented) and (Formula presented) single crystals using a miniature Hall-sensors array. Measurements in the field range corresponding to the anomalous magnetization peak in these crystals reveal remarkably different (Formula presented) characteristics below and above the peak, indicating a crossover in the flux-creep mechanism. Similar (Formula presented) behavior, as observed here in (Formula presented) and (Formula presented) is expected universally in every superconductor exhibiting the anomalous peak.