Abstract: A new type of hybrid nanomaterial composed of magnetic FePt nanoparticles grown on the surface of nanodiamond nanotemplate assemblies is described for the first time. Post annealing in vacuum of the as-made nanomaterial bearing cubic A1 soft magnetic FePt nanoparticles leads to the development of FePt nanoparticles with tetragonal L10 hard, magnetic-phase characteristics, leaving untouched the nanodiamond nanotemplate assemblies. X-ray diffraction, high-resolution transmission electron microscopy including chemical mapping (HRTEM/ HAADF), magnetization measurements, and 57Fe Mo¨ssbauer spectroscopy data show that the magnetic FePt nanoparticles, with average sizes of 3 and 8 nm in the as-made and annealed hybrids, respectively, are homogenously distributed within the nanodiamond template in both nanomaterials. As a consequence, their structural, morphological, and magnetic properties differ significantly from the corresponding properties of the nonsupported (free) as-made and annealed FePt nanoparticles with average sizes of 6 and 32 nm, respectively, developed by the same methods. This spatial isolation suppresses the sizegrowth of the FePt nanoparticles during the postannealing procedure, triggering superparamagnetic relaxation phenomena, which are exposed as a combination of hard and soft magnetic-phasecharacteristics.

Douvalis A.P.,  Bourlinos A.B., Tuček J., Čépe K., Bakas T., Zbořil R.: “Development of Novel FePt/nanodiamond hybrid nanostructures: L 10  phase size-growth suppression and magnetic properties“. J.Nanopart. Res., 18 (2016) 115.