Here the crystals have grown at different rates. A perfect sample is crystal clear, while flaws create patterns such as the staircase shown here. If a superconductor is built on such an imperfect surface, it can handle only a low level of electric current. This film, which was formed at high temperature, cooled too quickly. Since the molecules didn't have enough time to settle into their most comfortable arrangement making a perfect crystal-flaws became locked into the structure.
Thin films can trick the eye.
This is a stack of alternating nickel oxide and iron oxide layers known as a superlattice. By combining materials with different magnetic properties. Researchers can come up with new and unexpected properties in superlattices, such as enormously intense magnetic fields that may turn out to be excellent for computer memory suorage. But in this picture the superlattice itself, a few dozen atoms thick, is invisible. What looks like an angled photograph of miniature cliffs and ridges is actually a view of cracks in the surface wafer from directly overhead.