OPTICAL AND MAGNETIC PROPERTIES OF FE NANOPARTICLES FABRICATED BY FS LASER ABLATION IN ORGANIC AND INORGANIC SOLVENTS

JESICA M. J. SANTILLÁN; DAVID MUÑETÓN ARBOLEDA; DIEGO F. CORAL; MARCELA B. FERNÁNDEZ VAN RAAP; DIEGO MURACA; DANIEL C. SCHINCA ; LUCÍA B. SCAFFARDI

Chem Phys Chem

Wiley InterScience

Lugar: Berlin; Año: 2017 vol. 18 p. 1192 - 1209

1439-7641

Magnetic nanoparticles have attracted much interest due to their broadapplications in biomedical and pollutant remediation areas. In this paper, we study the optical, magnetic and structural characteristics of colloids produced by ultrashort pulsed laser ablation of a solid Fe target immersed in four different media: HPLC water, trisodium citrate aqueous solution, acetone and ethanol. Optical extinction spectroscopy reveals an absorption band in the UV region for all solvents except acetone, differing from what is obtained with ns lasers. Micro-Raman spectroscopy shows that the samples are heterogeneous in their composition, having hematite, maghemite and magnetite nanoparticles in the four solvents. Similar results are obtained by electron diffraction, where also -Fe was found. Magnetic properties are studied by vibrating sample magnetometer, resulting in nanoparticles in superparamagnetic state. We alsoshow that, under certain experimental conditions, sub-micron sized iron oxidenanoparticles agglomerate following fractal patterns that show self-similar properties. Self-assembled annular structures in the nanometer scale are also observed and reported for the first time.