Effect of annealing on magnetic properties of Fe-doped SrTiO_3 nanopowders prepared by hydrothermal method

摘要

Fe-doped SrTiO_3 (SrTi_(1-x)Fe_xO_3) (x = 0, 0.05, 0.1 and 0.15) nanopowders were prepared by hydrothermal method. The structure and morphology of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Magnetic properties were measured at room temperature using a vibrating sample magnetometer (VSM). The product nanopowders show the major phase of cubic structure. The nanopowders consist of cubic-like particles with particles sizes in the range of 90-150 nm. Magnetic behavior of as-synthesized samples exhibit from paramagnetic to low saturation ferromagnetic with increasing Fe content and display the completed saturation ferromagnetic for samples annealed in Argon atmosphere. The ferromagnetic behavior in the annealed samples of x = 0.1 and 0.15 is due to the impurity phase of Fe metal. However, for annealed samples of x = 0.05 the observed ferromagnetic behavior is originated from the F-center mechanism.