Magnetic properties of nanometric Fe-based particles obtained by laser-driven pyrolysis

作者：David B^*; Pizurova N; Schneeweiss O; Klementova M; Santava E; Dumitrache F; Alexandrescu R; Morjan I

来源：Journal of Physics and Chemistry of Solids, 2007, 68(5-6): 1152-1156.

DOI：10.1016/j.jpcs.2007.03.017

• nanostructures
• vapor deposition
• electron microscopy
• mbssbauer effect
• magnetic properties

Fe-based nanoparticles were prepared by laser pyrolysis method using a cross-flow reactor in which the CO, laser radiation orthogonally crosses with the stream of Fe(CO)(5), C2H2, and C2H4 gases. The as-synthesised powder was characterised by HRTEM, XRD, Mossbauer spectroscopy, and low- and high-temperature magnetic measurements. The as-synthesised powder consisted of alpha-Fe and Fe3O4/gamma-Fe2O3 nanoparticles embedded in a pyrolytic carbon matrix. The XRD pattern of the sample exhibited broad peaks. The crystallite size d(XRD) was estimated using the Scherrer formula and it was 1.8 nm for alpha-Fe and 1.6 nm for pyrolytic carbon. The assynthesised nanopowder was superparamagnetic. The blocking temperature was determined from the maximum of the ZFC curve and it was 32 K. After the sample had been cooled down to 4 K, the Mossbauer-Lamb factor f strongly increased.

• 出版日期2007-6