Modulating the crystalline assembly of paramagnetic Au25 nanoclusters using an external magnetic field.

Metal nanoclusters hold great potential for their use as atomically precise building units to construct well-defined assembly structures with accurate structure-property correlation. The external field induction approach towards nanocluster assembly was considered to be beneficial for practical assembly and post-treatment. Herein, we report the modulation of the Au250 crystalline assembly structure using a magnetic field accompanied by thermal treatment. The introduction of a magnetic field gives rise to not only a more compact packing structure but also different influences on the ligands, staples, and kernel configuration. The magnetic field also has a significant impact on the magnetic behavior of Au250 single crystals including paramagnetism intensity and magnetic anisotropy. This work opens new avenues toward the control of the assembly structure and magnetic properties of metal nanoclusters.