Landau domain structure. II. Experiment

The Sharvin-Landau double-point-contact technique has been used to make an extensive study of the spatial periodicity $a$ of the Landau domain structure in the dynamic intermediate state of superconducting aluminum. The samples were thin flat plates with the magnetic field applied at a small angle to the large sample faces. An ancillary field was utilized in order to improve the regularity of the moving structure. Highly regular motion was achieved over a wide range of $C_N^{*}$, the fraction of the sample surface in the normal state. The dependence of $a$ upon $C_N^{*}$ was found to be in good agreement with a modified Landau-Sharvin theory.