Iron oxide materials produced by laser pyrolysis

4 páginas, 1 figura, 1 tabla.-- PACS: 81.20.-n, 42.62.-b, 75.47.Lx, 75.50.Tt, 82.30.Lp.-- et al.-- Comunicación presentada al Bonsai Project Symposium on Breakthroughs in Nanoparticles for Bio-Imaging.The laser pyrolysis technique was employed in the production of magnetic iron oxide nanometric powders due to its capability of producing highly homogeneous nanoparticles in continuous form. This technique consists of the laser-driven rapid heating of an iron precursor in vapor phase in presence of oxygen. Different samples were prepared by changing the experimental conditions of synthesis. We found that high crystallinities and good magnetic properties are attained at high density of the laser power and strong oxidation. By the contrary, softer conditions using low laser densities and soft oxidation conditions give in general smaller and poorly ordered nanoparticles. The particles obtained were in the range of 2 to 9 nm in diameter (TEM). All of them were superparamagnetic at room temperature with saturation magnetization values in the interval of 4–38 emu/g-sample. The samples consist in Fe2O3 maghemite with carbon as the main impurity present on the surface in the form of C = O bonds.This work was supported by the STREP FP6 E.U. Project Bio-Imaging with Smart Functional Nanoparticles (BONSAI) Nº LSHB-CT-2006-037639.Peer reviewe