Interface structure of SrTi O3 LaAl O3 at elevated temperatures studied in situ by synchrotron x rays

Abstract

The atomic interface structure between SrTi O3 and LaAl O3 was studied at elevated temperatures employing in situ surface x-ray diffraction. The results at 473 K indicate that the lattice distorts significantly in two ways. First, the interatomic distances between the cations across the interface become as large as 4.03 (2) Å. Second, the Ti O6 octahedra at the interface contract their principal axis along the surface normal considerably and the Ti displaces off center. These distortions can be ascribed to the charge inbalance introduced by the change in atomic species across the interface and to a Jahn-Teller effect. The latter distortion suggests the presence of extra electrons at the interface, which is important for understanding the electronic properties of this system. © 2007 The American Physical Society.