Magnetic hollow cages with colossal moments

A comprehensive study of the interaction of transition metal clusters with B, C, N, O, and Si reveal novel structure and properties: Co₁₂C₆, Mn₁₂C₆, and Mn₂₄C₁₈ clusters form stable ferromagnetic hollow cages with total magnetic moments of 14 μ_B, 38 μ_B, and 70 μ_B, respectively. Replacement of C with B, N, O, or Si has significant impact on their structure and magnetic properties. For example, Mn₂₀Si₁₂ cluster forms a ferrimagnetic dodecahedral hollow cage with a total magnetic moment of 36 μ_B while Mn₁₂N₆, X₁₂C₆ (X = Ni, Cu, Pd, Pt), and Cu₁₂O₆ possess no magnetic moment, although they retain hollow cage structures. Mn₁₂B₆ and Mn₂₄Si₁₈, on the other hand, form compact ferrimagnetic structures. Synthesis of hollow cage clusters with unique magnetic properties may lead to important applications.