Superconducting Material Diagnostics using a Scanning Near-Field Microwave Microscope

We have developed scanning near-field microwave microscopes which can image electrodynamic properties of superconducting materials on length scales down to about 2 $\mu$m. The microscopes are capable of quantitative imaging of sheet resistance of thin films, and surface topography. We demonstrate the utility of the microscopes through images of the sheet resistance of a YBa2Cu3O7-d thin film wafer, images of bulk Nb surfaces, and spatially resolved measurements of Tc of a YBa2Cu3O7-d thin film. We also discuss some of the limitations of the microscope and conclude with a summary of its present capabilities.