High-resolution scanning hall probe microscopy

A high resolution scanning Hall probe microscope is used to spatially resolve vortices in high temperature superconducting Bi2Sr2CaCu2O8+δ crystals. We observe a partially ordered vortex lattice at several different applied magnetic fields and temperatures. At higher temperatures, a limited amount of vortex re-arrangement is observed, but most vortices remain fixed for periods long compared to the imaging time of several hours even at temperatures as high as 75°K (the superconducting transition temperature for these crystals is ∼84°K). A measure of the local magnetic penetration depth can be obtained from a fit to the surface field of several neighboring vortices, and has been measured as a function of temperature. In particular, we have measured the zero temperature penetration depth and found it to be 275 ± 40 nm.

Duke Scholars

Author Albert M. Chang Physics

Author David Mitzi Thomas Lord Department of Mechanical Engineering and Materia ...