Moiré pattern produced by electron bombardment of a molybdenum trioxide single crystal

A single crystal of molybdenum trioxide bombarded by an intense beam of electrons in an electron microscope developed a new internal structure showing localized fringe patterns in different parts. The phenomenon is explained as being the result of recrystallization of MoO₃ up to only a certain depth in the crystal. The fringe pattern is a rotation moiré fringe pattern resulting from a slight misorientation. This interpretation is confirmed by selected area diffraction patterns.