Crystal structure, local structure, and defect structure of Pr-doped SrTiO$_3$

I. A. Sluchinskaya; A. I. Lebedev; A. Erko

doi:10.1063/1.4737586

paper

Crystal structure, local structure, and defect structure of Pr-doped SrTiO $_{3}$

arXiv:1203.3066 · doi:10.1063/1.4737586

Abstract

X-ray diffraction studies showed that the structure of (Sr $_{1 - x}$ Pr $_{x}$ )TiO $_{3}$ solid solutions at 300 K changes from the cubic $P m 3 m$ to the tetragonal $I 4/ m c m$ with increasing $x$ . The analysis of XANES and EXAFS spectra of the solid solutions revealed that Pr ions are predominantly in the 3+ oxidation state, they substitute for Sr atoms and are on-center regardless of the preparation conditions. The weak dependence of the lattice parameter in (Sr $_{1 - x}$ Pr $_{x}$ )TiO $_{3}$ on the Pr concentration was explained by the competition between the relaxation of the Sr--O bond length, which results from the difference in ionic radii of Sr and Pr ions, and the repulsion of positively charged Pr $^{3 +}$ and Ti $^{4 +}$ ions. It was shown that the most important defects in the crystals are charged Sr vacancies and SrO planar faults; praseodymium does not enter the Sr sites in the planar faults.

6 pages, 4 figures, 1 table

Crystal structure, local structure, and defect structure of Pr-doped SrTiO3​

Abstract

Crystal structure, local structure, and defect structure of Pr-doped SrTiO $_{3}$