SUPERCONDUCTOR SCIENCE & TECHNOLOGY, cilt.10, ss.17-20, 1997 (SCI İndekslerine Giren Dergi)
We have used a low noise scanning Hall probe microscope to measure the penetration depth microscopically in a YBa2Cu3O7-delta thin film as a function of temperature. The instrument has high magnetic field (approximate to 2.9 x 10(-8) T HZ(-1/2) at 77 K) and spatial resolution ( approximate to 0.85 mu m). Magnetic field profiles of single vortices in the superconducting film have been successfully measured and the microscopic penetration depth of the superconductor has been extracted. We find surprisingly large variations in values of lambda for different vortices within the scanning field.