STM image of Mn3N2 (010) showing atomically-smooth terraces. Each step shown
has a height of one monolayer of manganese nitride which has the face-centered tetragonal,
rock-salt structure but with planes of N vacancies standing perpendicular to the surface.
For more details, see "Structural and Magnetic Properties of eta-phase Manganese Nitride Films Grown by Molecular Beam Epitaxy",
Appl. Phys. Lett. 78, 3860 (2001).