Observations of cobalt smoke particle

Cobalt smoke particle observed by electron interference microscopy

We can observe only the triangular outline of this particle by electron microscopy. While, in its interference micrograph, two kinds of phase contours appear: narrow fringes parallel to the particle edges indicate thickness contours, and circular fringes in the inner region indicate in-plane magnetic lines of force in h/(2e) magnetic flux units due to the twofold phase amplification.