Alternative low-cost approach to the sythesis of magnetic iron oxide nanoparticles by thermal decomposition of organic precursors

I.O. PEREZ DE BERTI; M.V. CAGNOLI; G. PECCHI; J L ALESSANDRINI; S J STEWART; J F BENGOA; S G MARCHETTI

NANOTECHNOLOGY

IOP PUBLISHING LTD

Lugar: Londres; Año: 2013 vol. 24 p. 175601 - 175612

0957-4484

A new approach to thermal decomposition of organic iron precursors is reported, which results in a simpler and more economical method to produce well crystallized gamma-Fe2O3 nanoparticles (NPs) with average sizes within the 3?17 nm range. The NPs were characterized by TEM, SAED, XRD, DLS-QELS, Möossbauer spectroscopy at different temperatures, FT-IR and magnetic measurements. The obtained gamma-Fe2O3 NPs are coated with oleic acid and, in a lower quantity, with oleylamine (about 1.5 nm in thickness). It was shown that changing operative variables allows us to tune the average particle diameters and obtain a very narrow or monodisperse distribution of sizes. The Fe2O3 NPs behave superparamagnetically at room temperature and their magnetization saturation is reduced by about 34% in comparison with bulk maghemite. The results indicate that the distance between two neighbour NPs, generated by the coating, of about 3 nm is insufficient to inhibit interparticle magnetic interactions when the average diameter is 8.8 nm. The good quality of the NPs, obtained through the present low-cost and easy-handling process, open a new perspective for future technological applications.