Structures of stanene with (a) full- and (b)–(c) half-passivation by I atoms. Large gray and small pink spheres represent the Sn and I atoms, respectively. For the half-passivated stanene, unpassivated Sn sites exhibit magnetic moments in a triangular lattice (dotted lines), which are indicated by the blue arrows. The FM and 120° AFM phases are indicated in panels (b) and (c), respectively. The spin charge density is shown in an isovalue surface plot, which distributes primarily at the unpassivated Sn atoms. The isovalue of the spin density is chosen as 0.006 electron/ų. Reprinted with permission from Ref. [24]. Copyright 2014 by the American Physical Society.