Easy synthesis and characterization of γ-Fe2O3 nanoparticles for biomedical applications

Easy syntheses of γ-Fe2O3 nanoparticles have been fabricated by the sol–gel method. The powders present average particle size of 7, 10, and 13nm with narrow size distribution for samples as-obtained and annealed at 150, 175, and 200°C, respectively. At a room temperature, 10nm particles were partially superparamagnetic. The Mössbauer spectrum for the 7nm samples at room temperature displays superparamagnetic behavior as demonstrated by the single quadrupole doublet with zero hyperfine fields. Superparamagnetic particles display no sextet in Mössbauer spectra at temperatures above blocking temperature (TB=165K for the 7nm sample).