Study on Defects in Fe-Doped SrTiO3 by Positron Annihilation Lifetime Spectroscopy
JIN Yuanyuan, LI Xiaodong, HAO Yao, LI Jingjing, WANG Zhu†Key Laboratory of Nuclear Solid State Physics Hubei Province / School of Physics and Technology, Wuhan University, Wuhan 430072, Hubei, China
SrTi1-xFexO3-d ceramics were prepared using a traditional solid-state reaction method. From X-ray diffraction (XRD) result, we found that the doped Fe3+ dissolved in the lattice, and no secondary phase was observed. Cation vacancies in perovskite oxides were identified via positron annihilation lifetime spectroscopy (PALS) measurements. Undoped and Fe-doped SrTiO3 ceramics and single-crystal SrTiO3 were measured by PALS at room temperature. The results show that the main defects in undoped SrTiO3 ceramics are Ti-related defects, and the isolated Ti vacancy lifetime is about 183.4 ps. With the increase of Fe3+, the concentration of the Ti vacancies decreases accompanied by the appearance of the (defect association of Sr vacancies and multiple O vacancies) vacancy defect complexes.
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