Magnetic imaging and dissipation force microscopy of vortices on superconducting Nb films

Constant height imaging using a custom built low temperature magnetic force microscope has been performed on patterned and unpatterned superconducting Nb films. Tip induced motion of the vortices is shown, as a function of both tip–sample separation and temperature. Constant height dissipation images of vortices suggest eddy current damping as well as vortex motion within potential wells as major sources of energy loss.