Abstract
Epsilon-Fe2O3/SiO2 nanocomposite was prepared by novel solgel method using single precursor for both nanoparticles and matrix. This method allows to prepare the samples free of alpha-Fe2O3 with 40% of Fe2O3 in SiO2.
Nanoparticles of 12 nm diameter were obtained by annealing at 1,000 A degrees C. The samples were characterized by powder X-ray diffraction and transmission electron microscopy.
Mossbauer spectroscopy identified epsilon-Fe2O3 as the only magnetically ordered phase at room temperature. Magnetic measurements revealed progressive necking of hysteresis loops measured at 300 and 2 K.
In both cases the intrinsic coercivity reaches only 0.25 T. Measurements up to 14 T shows monotonous decreasing trend of saturated magnetization with increasing temperature.