Distance-dependent magnetization modulation induced by inter-superatomic interactions in Cr-doped Au₆Te₁₂Se₈ dimers

Abstract Individual superatoms are assembled into more complicated nanostructures to diversify their physical properties. Magnetism of assembled superatoms remains, however, ambiguous, particularly in terms of its distance dependence. Here, we report density functional theory calculations on the distance-dependent magnetism of transition metal embedded Au 6 Te 8 Se 12 (ATS) superatomic dimers. Among the four considered transition metals, which include V, Cr, Mn and Fe, the Cr-embedded Au 6 Te 12 Se 8 (Cr@ATS) is identified as the most suitable for exploring the inter-superatomic distance-dependent magnetism. We thus focused on Cr@ATS superatomic dimers and found an inter-superatomic magnetization-distance oscillation where three transitions occur for magnetic ordering and/or anisotropy at different inter-superatomic distances. As the inter-superatomic distance elongates, a ferromagnetism (FM)-to-antiferromagnetic (AFM) transition and a sequential AFM-to-FM transition occur, ascribed to competitions among Pauli repulsion and kinetic-energy-gains in formed inter-superatomic Cr–Au–Au–Cr covalent bonds and Te–Te quasi-covalent bonds. For the third transition, in-plane electronic hybridization contributes to the stabilization of the AFM configuration. This work unveils two mechanisms for tuning magnetism through non-covalent interactions and provides a strategy for manipulating magnetism in superatomic assemblies.