Dispersible ferromagnetic FePt nanoparticles

The dispersion of FM fct-FePt NPs prepared from thermal annealing of the core/shell structured fcc-FePt/MgO NPs was studied. Monodisperse FePt NPs was produced by solution-phase chemical decomposition of iron pentacarbonyl and reduction of platinum acetylacetonate or by reduction of an iron and a platinum salt. The high temperature annealing renders FM FePt NPs undispersible, and unsuitable for controlled assembly and for single-particle magnetism studies. The experiment carried out the synthesis of fcc-Fe₅₁Pt₄₉, by the addition of oleic acid and oleylamine into a 50 mL four neck flask that contained 10mL of octadec-1-ene under gentle argon gas flow. The size, morphology and structure were characterized using a Philips EM 420 and a JEOL 2010. The result shows that the MgO in the fct-FePt/MgO can be removed by acid (HCl) washing, and the fct-FePt NPs are protected by a surfactant combination of hexadecanethiol and oleic acid, forming a stable hexane dispersion.