First-principles structural stability in the strontium–titanium–oxygen system

Abstract

First principles calculations have been made to theoretically interpret the structural stability of SrTiO₃ as a function of pressure or strain. We show that the orthorhombic Pbnm structure is more stable than the ideal perovskite one due to rotations of TiO₆ octahedrons at high pressures or deformations of TiO₆ octahedrons at low pressures. Such a study is extended to the structural stability of the Ruddlesden–Popper Sr _{n +1}Ti _n O_{3 n +1} phases for n = 1, 2 and 3, in which the lattice constraints are induced by the intercalation of SrO layers in the perovskite structure.

Acknowledgments

We acknowledge Laboratoire de Physique et Modélisation des Milieux Condensés for computational resources on the PC cluster PHYNUM (CIMENT, Grenoble).