10.1021/acs.nanolett.8b05083.s001 Cyril Garnero Cyril Garnero Mathieu Lepesant Mathieu Lepesant Cécile Garcia-Marcelot Cécile Garcia-Marcelot Yooleemi Shin Yooleemi Shin Christian Meny Christian Meny Pierre Farger Pierre Farger Bénédicte Warot-Fonrose Bénédicte Warot-Fonrose Raul Arenal Raul Arenal Guillaume Viau Guillaume Viau Katerina Soulantica Katerina Soulantica Pierre Fau Pierre Fau Patrick Poveda Patrick Poveda Lise-Marie Lacroix Lise-Marie Lacroix Bruno Chaudret Bruno Chaudret Chemical Ordering in Bimetallic FeCo Nanoparticles: From a Direct Chemical Synthesis to Application As Efficient High-Frequency Magnetic Material American Chemical Society 2019 FNR ligand Material Single-crystalline FeCo nanoparticles X-ray diffraction studies as-prepared nanoparticles exhibit precursor presence Bimetallic FeCo Nanoparticles synthesis FeCo nanoparticles B 2 structure chemical Direct Chemical Synthesis 2019-02-13 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Chemical_Ordering_in_Bimetallic_FeCo_Nanoparticles_From_a_Direct_Chemical_Synthesis_to_Application_As_Efficient_High-Frequency_Magnetic_Material/7712081 Single-crystalline FeCo nanoparticles with tunable size and shape were prepared by co-decomposing two metal-amide precursors under mild conditions. The nature of the ligands introduced in this organometallic synthesis drastically affects the reactivity of the precursors and, thus, the chemical distribution within the nanoparticles. The presence of the B2 short-range order was evidenced in FeCo nanoparticles prepared in the presence of HDAHCl ligands, combining <sup>57</sup>Fe Mössbauer, zero-field <sup>59</sup>Co ferromagnetic nuclear resonance (FNR), and X-ray diffraction studies. This is the first time that the B2 structure is directly formed during synthesis without the need of any annealing step. The as-prepared nanoparticles exhibit magnetic properties comparable with the ones for the bulk (<i>M</i><sub>s</sub> = 226 Am<sup>2</sup>·kg<sup>–1</sup>). Composite magnetic materials prepared from these FeCo nanoparticles led to a successful proof-of-concept of the integration on inductor-based filters (27% enhancement of the inductance value at 100 MHz).