Fabrication of ferromagnetic nanocluster rods by magnetic trapping

In a one-pot fabrication at room temperature, both an iron-neodymium-dysprosium-boron permanent magnet (Fe66Nd28Dy4B1) and cobalt (Co) metal have been directly converted into the corresponding ferromagnetic nanometer-scale cluster (nanocluster) rods using pulsed-laser ablation combined with magnetic-field trapping. The morphology of the produced nanomaterials was analyzed by electron microscopy and the composition by electron energy-loss spectroscopy, and it was found that one-dimensional structured soft magnets, up to ∼150 nm in length, consist of magnetic clusters a few nanometers in diameter. The mechanism and driving behind their growth process and their magnetic evolution have been proposed.