Magnetic property and 57Fe Mössbauer analysis of dilute Fe and Nb codoped SrTiO3-δ(STO) perovskites

Dilute Fe and Nb codoped SrTiO3-δ (STO) perovskites were prepared by a complex formation and thermal decomposition method. The structure, magnetization properties and chemical states of Fe and Nb codoped STO perovskites were characterized by XRD, VSM and Mössbauer spectrometry. Mössbauer spectra of 57Fe and Nb codoped STO perovskites consist of paramagnetic doublet and magnetic relaxation components. The 1% Fe + 5% Nb codoped STO sample showed the smallest lattice constant and the largest ferromagnetism among 0.5–4% Fe + 5% Nb codoped STO perovskites. The most distortion of cubic STO lattice and the largest magnetic relaxation in Mössbauer spectrum were observed for the 0.5% Fe and 5% Nb codoped STO perovskite. It is considered that diluted magnetism in this system is related with the deformation of cubic structure due to defects.