Regulating the morphology and structures of wet-chemical synthesized L 1 0 -FePtMn nanoparticles by applying magnetic fields.

We report an effective strategy to prepare highly ordered L 1 0 -FePt nanoparticles (NPs) by magnetic-field-assisted wet-chemical synthesis. The Mn element with high magnetic susceptibility was chosen for third-element addition, which is beneficial to reduce the required magnetic field strength for ordering transition. The evolution of morphology, ordering degree, and magnetic properties of the FePtMn nanomaterials in the synthesis process were systematically investigated. The attachment of spherical FePtMn NPs was facilitated by applying magnetic fields. The particle size was refined only when the magnetic field strength was as high as 6 T. The ordering degree and coercivity of NPs have been improved and reached the peak values when the magnetic field was 2 T, which can be easily achieved by using an ordinary electromagnet. Therefore, this work provides a feasible route for regulating the morphology and structural ordering of L 1 0 -phase ternary alloy NPs.