Magnetic fluid: Comparative study of nanosized Fe3O4 and Fe3O4 suspended in Copaiba oil using Moessbauer spectroscopy with a high velocity resolution

Comparative study of nanosized magnetite and magnetite suspended in Copaiba oil (biocompatible magnetic fluid) was made using Moessbauer spectroscopy with a high velocity resolution (spectra were measured in 4096 channels). The better fit of room temperature spectra was done using 15 sextets and 1 doublet employing different parameters while spectra measured at 90 K were better fitted using 15 sextets with different parameters. These component numbers were related to multi-domain structure and non-stoichiometry of magnetite. Observed differences of magnetic hyperfine fields and relative areas of spectral components for nanosized Fe3O4 and Fe3O4 suspended in Copaiba oil may be related to the effect of surface interactions of Fe3O4 and polar molecules of Copaiba oil.