Exchange-coupled FePt nanoparticle assembly

Abstract

Synthesis of exchange-coupled FePt nanoparticle assemblies via solution-phase deposition and controlled thermal annealing were presented. FePt nanoparticles were prepared by high temperature solution phase decomposition of Fe(CO)5 and reduction of Pt(acac)2 in the presence of oleic acid and oleyl amine. Remanence curves and magnetic hysteresis loops, showed that annealing for short time under nitrogen yielded isolated particle assemblies with random crystalline orientations. Changes in the magnetization reversal behavior were observed and the degree of coupling could be controlled by annealing conditions.