The Fe K-edge X-ray absorption fine structure (XAFS) spectra of BaFe0.5Nb0.5O3 were analyzed together with those of Fe2O3 and CaFe0.5Sb0.5O3, which were used as reference compounds. Both X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) have been employed to obtain quantitative structural information on the Fe local environment. A substantial pre-edge peak at the absorption spectra of BaFe0.5Nb0.5O3 shows that the symmetry of the structure is not cubic on the local scale due to Fe displacement off the center of the oxygen octahedron. The values of Fe-O distances were refined by a nonlinear least-square fit to the EXAFS data, and the Fe off-center displacement was estimated to be about 0.12 Å. The results show that BaFe0.5Nb0.5O3 possesses quite substantial local dipole moments, which may have an impact on its dielectric properties.
- Electronic materials
- Local structure