LAUSR

Breaking the inversion symmetry in artificial hetero-structures is proving to be a powerful approach to create novel quantum states, thereby providing new functionalities with potential for the development of revolutionary devices. Based on this, a way to achieve “hybrid improper ferroelectricity” in perovskite superlattices was recently devised by ab-initio theory [1, 2]. The working principle rests on the stacking of odd numbers of orthorhombic distorted ABO3 and A’BO3 unit cells in order to generate a macroscopic polarization out of the uncompensated displacements of the A site cations in the superlattice. These displacements are the result of the strong coupling between chemistry and structure in perovskite oxides. Towards this goal, here we investigate AVO3 epitaxial thin films grown under different conditions by pulsed laser deposition, where A is either La or Pr, using aberration-corrected scanning transmission electron microscopy (STEM) to identify local strain-induced structural and compositional effects.