Off-centering of the Fe atom at the A site in SrTiO₃: calculations and experiment

Abstract

The influence of annealing temperature and deviation from stoichiometry on the incorporation of the Fe impurity into the A and B sites of the perovskite structure is studied using XAFS spectroscopy and X-ray diffraction. It is shown that at high annealing temperature about 30% of the iron atoms enter the A sites in SrTiO₃. The obtained results agree with the results of first-principles calculations, according to which the Fe²⁺ ion at the A site exhibits strong off-centering (the displacement of ∼1 Å). The mechanism of magnetoelectric interaction for magnetic off-center ions is discussed.

Keywords:

• Iron
• doping
• strontium titanate
• XAFS
• off-center ions

Acknowledgment

The authors express their gratitude to BESSY staff for the opportunity to carry out our experiments and support of this project.