Magnetic property and Mössbauer analysis of SrSn_1−xFe_xO₃ prepared by a sol-gel method

The dilute magnetic properties of SrSn_1−xFe_xO₃ (x = 0.01 − 0.15) prepared by sol-gel and thermal decomposition methods were investigated by ⁵⁷Fe Mössbauer spectrometry, magnetometry, and X-ray diffractometry. It was found that SrSnO₃ doped with 2–8 % Fe show weak ferromagnetism although only paramagnetic doublets are observed in ⁵⁷Fe Mössbauer spectra at room temperature (RT), whereas SrSnO₃ doped with 10–15 % Fe show relatively strong ferromagnetism, and the sextets are additionally observed in the ⁵⁷Fe Mössbauer spectra at RT. The weak ferromagnetism by doping 2–8 % Fe is considered to be caused by the induced magnetic defects, and the ferromagnetism by doping 10–15 % Fe are considered mainly due to the magnetic coupling between dilute Fe ³⁺ partially substituted at Sn ⁴⁺ sites in the orthorhombic structure of SrSnO_3−δ accompanying the oxygen deficiencies. It is further remarkable that poor crystalline 8 % Fe doped SrSnO_3−δ obtained by annealing at 600 ^∘C shows relatively high saturation magnetization and low coercivity.