부산대학교 도서관

Herein we report the synthesis and properties of Fe55Pt45 nanoparticles, both monodisperse and self-assembled into hexagonal close-packed and cubic arrays of 4.0 ± 0.2 nm size in an L10 structure, obtained by a modified polyol process. The new synthetic route improved the control over the particle composition, thereby reducing the temperature required to convert from face-centered cubic (fcc) to face-centered tetragonal (fct) phase by some 30-50 °C without additives. Annealing at 550 °C for 30 mm converts the self-assembled nanoparticles into ferromagnetic nanocrystals with large coercivity, HC = 11.1 kOe. Reducing the fcc-to-fct (L10) ordering temperature avoided particle coalescence and decreased the loss in particle positional order without compromising the magnetic properties, as is generally observed when additives are used. [ABSTRACT FROM AUTHOR]