Misfit Strain Accommodation in Epitaxial ABO3 Perovskites: Lattice Rotations and Lattice Modulations

TL;DR

This study investigates how misfit strain influences lattice distortions, rotations, and modulations in epitaxial ABO3 perovskite thin films, revealing strain-dependent structural changes that impact their magnetic and electronic properties.

Contribution

It demonstrates how biaxial stress modifies lattice structures and octahedral rotations in epitaxial ABO3 perovskites, providing insights into strain-controlled property tuning.

Findings

Lattice structures shift from orthorhombic/rhombohedral to monoclinic/tetragonal under strain.

Octahedral rotations are controlled by the magnitude and sign of misfit strain.

Lattice distortions influence magnetic and electronic properties of the materials.

Abstract

We present a study of the lattice response to the compressive and tensile biaxial stress in La0.67Sr0.33MnO3 (LSMO) and SrRuO3 (SRO) thin films grown on a variety of single crystal substrates: SrTiO3, DyScO3, NdGaO3 and (La,Sr)(Al,Ta)O3. The results show, that in thin films under misfit strain, both SRO and LSMO lattices, which in bulk form have orthorhombic (SRO) and rhombohedral (LSMO) structures, assume unit cells that are monoclinic under compressive stress and tetragonal under tensile stress. The applied stress effectively modifies the BO6 octahedra rotations, which degree and direction can be controlled by magnitude and sign of the misfit strain. Such lattice distortions change the B-O-B bond angles and therefore are expected to affect magnetic and electronic properties of the ABO3 perovskites.