Study of iron oxide magnetic nanoparticles obtained via pulsed laser ablation of iron in air.

Graphical abstract Highlights • Pulsed laser ablation of iron in air led to magnetite and iron nitrides formation. • Lamellas and rolls appear in the sample that was ablated in air, not in Ar-O 2 mixture. • Thermal treatment allowed control of the composition and structure of the material. • Materials obtained with different properties are in demand for different applications. Abstract Magnetic nanoparticles were obtained using the nanosecond pulsed laser ablation (Nd:YAG laser, 1064 nm, 7 ns) of an iron target in air at atmospheric pressure. The particles obtained were further annealed at four different temperatures. The composition, structure and properties of all obtained powders were investigated using X-ray diffraction (XRD), DSC, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, TEM, SAED and other techniques. The initial sample was found to contain monoclinic magnetite and iron nitrides. Presumably, magnetite presents in the form of spherical particles with the distribution maximum of 12–15 nm, and nitrides take the form of lamellas and rolls. Thermal treatment of the sample led to particle enlargement and phase transformations, first, to cubic magnetite, then to a Fe 3 O 4 , α-Fe 2 O 3 and γ-Fe 2 O 3 mixture, and finally to the pure hematite phase. Zeta-potential, BET surface area and magnetic properties changed with the annealing as well. The obtained materials exhibited different properties that make them in demand in different fields, from biomedicine to technology. [ABSTRACT FROM AUTHOR]