Direct observation of the interaction between vortices and dislocations insuperconducting crystals by a cryo-Lorentz EM (interaction between vortices and dislocations)
S. Horiuchi et al., Direct observation of the interaction between vortices and dislocations insuperconducting crystals by a cryo-Lorentz EM (interaction between vortices and dislocations), B MATER SCI, 22(3), 1999, pp. 227-231
Quantized magnetic nux lines (vortices) in a Nb foil were directly observed
in different magnetic fields up to 200 G by a cryo-lorentz electron micros
cope. The interaction of vortices with dislocations in the specimen was exa
mined and clarified; edge-on dislocations weakly pin individual vortices at
magnetic fields below 100 G, In higher magnetic fields the formation of a
regular hexagonal vortex lattice started preferentially at in-plane disloca
tions. At 200 G the Abrikosov vortex lattice was formed with small domains,
whose centre included the dislocations, showing their important role on th
e formation of the vortex lattice. For a NbTi foil no clear image of vortic
es could be seen, because the surface was rough due to the formation of fin
e grains and precipitates.