Simulation of STEM-HAADF image contrast of Ruddlesden-Popper faulted LaNiO₃ thin films

Abstract

LaNiO3 (LNO) thin films are widely used as electrode materials. Yet, their properties greatly depend on such parameters as strain state and defect density. In this work we present a detailed structural characterization of epitaxial LNO thin films grown on LaAlO3(001). Based on scanning transmission electron microscope - high-angle annular darkfield imaging (STEM-HAADF) contrast analysis and image simulations, Ruddlesden-Popper faulted configurations, with 1/2a<111> relative displacement of defect free perovskite blocks, are atomically modeled and simulated to disentangle the variation of Z-contrast in the experimental images