Effect of annealing on magnetic properties of Fe-doped SrTiO3 nanopowders prepared by hydrothermal method

• SrTi1−xFexO3 nanopowders were synthesized by hydrothermal at 220 °C for 24 h.
• TEM images reveal a cubic-like particle with size in the range of 90–150 nm.
• All Fe-doped samples show paramagnetic behavior.
• Annealing of doped samples in Ar increases oxygen vacancy inducing ferromagnetism.

Fe-doped SrTiO3 (SrTi1−xFexO3) (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.

This figure shows magnetization curves and XPS (O 1s) spectra of the as-prepared and Ar-annealed SrTi0.95Fe0.05O3 nanopowders. The as-prepared sample behave paramagnetic, whereas the Ar-annealed sample is ferromagnetic due to the increasing of oxygen vacancies supported by the XPS results.Figure optionsDownload as PowerPoint slide