Fabrication of One-Dimensional Chain of Iron-Based Bimetallic Alloying Nanoparticles with Unique Magnetizations

One-dimension (1D) chains of magnetic nanoparticles (MNPs) are attractive due to their wide applications in new materials and devices. The fabrication of 1D chains of MNPs especially for bimetallic alloys such as iron-based bimetallic alloys MNPs is still a challenge considering the difficulty in the formation of alloying MNPs and the self-assembly process. Herein, we reported that a novel technique [i.e., the magnetic field assisted laser ablation in liquid (MF-LAL)], has been used to fabricate 1D chains of MNPs of iron-based bimetallic alloys of FePt, FeCo, and FeNi within one-step, taking a significant step toward the fabrication of functional nanomaterials and nanostructures. These 1D chains of alloying MNPs are ferromagnetic with high saturation magnetizations, low coercivity, and remanent magnetization, implying they are useful in the areas of magnetotransporters, micromechanical sensors, magnetic memory materials, DNA separation materials, and so on. A thermodynamic model has been established to address the assembly mechanism of 1D chains of alloying MNPs upon the MF-LAL process and the results showed that MF-LAL is a general, facile, and green strategy for fabricating 1D chains of alloying MNPs. These studies are useful for researchers to choose target materials and liquid mediums for the fabrication of 1D chains of MNPs for purpose of fundamental issues and applications via the MF-LAL technique.