Mechanochemical synthesis and magnetic properties of maghemite

This work presents the results of an investigation on maghemite (γ -Fe2O3) nanoparticles magnetic properties, which show superparamagnetic behavior i.e. superparamagnetism. Nanoscale maghemite samples were obtained by the mechanochemical method. The crystal structure of the samples was analyzed by the electron diffraction and the X-ray powder diffraction. The formation of monophase maghemite was shown. The particle size was determined by the transmission electron microscopy (TEM). The shift of the blockage temperature TB towards lower values with increasing field strength is significant, which is the indication of the superparamagnetism in the system under consideration