Abstract

Three Fe(β-diketonate)<inf>3</inf> compounds namely Fe(tmhd) <inf>3</inf> (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionato), Fe(hfac) <inf>3</inf> (hfac = hexafluoroacetylaceto), and Fe(dbm)<inf>3</inf> (dbm = dibenzoylmethane) were used as substitutes to Fe(acac)<inf>3</inf> (acac = acetyleacetonate) in the synthesis of FePt nanoparticles. The obtained superparamagnetic nanoparticles are 4-5 nm in diameter without showing a large size variation with substituent Fe(β-diketonate)<inf>3</inf>. The synchrotron X-ray absorption spectroscopy confirmed the energy dispersive spectroscopy that as-synthesized nanoparticles were composed of iron oxides and metallic FePt<inf>3</inf> alloys. By employing Fe(hfac)<inf>3</inf>, the Fe fraction was reduced and the magnetization was modest. The use of Fe(dbm) <inf>3</inf> as starting materials gave rise to densely packed FePt <inf>3</inf>/Fe<inf>2</inf>O<inf>3</inf> heterodimers. The replacements of Fe(acac)<inf>3</inf> by Fe(tmhd)<inf>3</inf> led to the long-range order of nanoparticle assembly with the narrowest size distribution. © Springer Science+Business Media 2014.