Figure 7

Orientations of Ni-triangles (within the rhombohedral unit cell) shown for (a) the 3-link model, where all triangles are identically linked and (b) the two-link model. Ni(II) ions are labeled A, B, and C. The kagome structure is formed by joining vertices in one triangle with their identically labeled vertices in the other, as has been done for the 2-link case in (c). In (b) exchange pathways between linked (unlinked) Ni(II) ions are represented by double (single) lines with the exchange constant J|| (J|). (c) Lowest energy configuration for a magnetic model of Ising-like spins for the 2-link model.