CONICET | Buscador de Institutos y Recursos Humanos

First-principles calculations based on density?functional theory in the pseudo-potentialapproach have been performed for the total energy, crystal structure and cell polarization forSrTaO2N/SrTiO3 heterostructures. Different heterojunctions were analyzed in terms of thetermination atoms at the interface plane, and periodic or non-periodic stacking in theperpendicular direction. The calculations show that the SrTaO2N layer is compressed alongthe ab-plane, while the SrTiO3 is elongated, thus favoring the formation of P4mm localenvironment on both sides of the interface, leading to net macroscopic polarization. Theanalysis of the local polarization as a function of the distance to the interface, for eachindividual unit cell was found to depend on the presence of a N or an O atom at the interface,and also on the asymmetric and not uniform c-axis deformation due to the induced strain in the−2 ab-plane. The resulting total polarization in the periodic array was ≈ 0.54 C m which makes this type of arrangement suitable for microelectronic applications.