Vortex creep was observed in magnetic fields of up to 4T at low temperatures (0.45K) in a type-II superconductor YNi2B2C by means of scanning tunnelling microscopy. The measurement time for one scanning tunnelling microscopy image was about 15s. The fast scanning tunnelling microscopy measurements permitted the observation of vortex motions in real time and space. Vortex lattices in the high magnetic field were found to be divided into vortex bundles separated by the glide planes of edge dislocations. The elementary motion of the vortex creep was the relative slide between vortex bundles mediated with the glides of dislocations

Importance of Dislocations in Vortex Creep Revealed in YNi2B2C by Observations in Real Time and Space by STM. K.Uchiyama, S.Suzuki, A.Kuwahara, K.Yamasaki, S.Kaneko, H.Takeya, K.Hirata, N.Nishida: Physica C, 2010, 470[1], S795-6