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arXiv · 1307.5082

Structural position and oxidation state of nickel in SrTiO3

Irina A. Sluchinskaya·Alexander I. Lebedev·Alexei Erko
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Abstract

The properties of Ni-doped strontium titanate are studied using X-ray diffraction and XAFS spectroscopy. It is shown that regardless of the preparation conditions, the SrTi1-xNixO3 solid solution and the NiTiO3 phase are the most stable phases which can coexist. According to the EXAFS data, in the single-phase sample of SrTi0.97Ni0.03O3, the Ni atoms substitute for the Ti ones and are on-center. The distortion of the oxygen octahedra is not observed. The XANES spectra analysis shows that the oxidation state of nickel in NiTiO3 is 2+, and in the SrTi1-xNixO3 solid solution it is close to 4+. It is shown that the strongest light absorption in doped samples is associated with the presence of tetravalent nickel in the SrTi1-xNixO3 solid solution. This doping seems the most promising one for solar energy converters that exploit the bulk photovoltaic effect.

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Irina A. Sluchinskaya, Alexander I. Lebedev, Alexei Erko. 2013-10-02. Structural position and oxidation state of nickel in SrTiO3. https://doi.org/10.1134/s1063783414030329

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