Highly regular domain motion in the dynamic intermediate state of superconducting tin

Using the Sharvin point-contact technique, the regularity of domain motion in the dynamic intermediate state of superconducting tin has been investigated as a function of temperature, applied magnetic field, and transport current. We have found that, when the magnetic field is increased so as to lie in a range closer to the critical field than has been previously investigated systematically, an extremely drastic increase in the regularity of the motion occurs, independent of temperature and sample condition. It is suggested that this drastic increase represents the onset of motion of a modified Landau domain structure, freed from the perturbing influence of the ends of the sample. A new phenomenon of "domain healing" is reported in the highly regular regime.