First-Principles Study of the Ferroelectric Properties of SrTaO2N/SrTiO3 Interfaces

First-principles calculations based on density-functional theory in the pseudo-potential approach have been performed for the total energy, crystal structure and cell polarization for SrTaO2N/SrTiO3 heterostructures. Different heterojunctions were analyzed in terms of the termination atoms at the in...

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Bibliographic Details
Authors: Bastidas Briceño, Ruby Carolina, Fernandez, Victoria Ines, Peltzer y Blanca, Eitel Leopoldo, Alonso, Roberto Emilio
Format: article
Status:Published version
Publication Date:2019
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/136791
Online Access:http://hdl.handle.net/11336/136791
Access Level:Open access
Keyword:FERROMAGNETISM
AB INITIO CALCULATION
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Description
Summary:First-principles calculations based on density-functional theory in the pseudo-potential approach have been performed for the total energy, crystal structure and cell polarization for SrTaO2N/SrTiO3 heterostructures. Different heterojunctions were analyzed in terms of the termination atoms at the interface plane, and periodic or non-periodic stacking in the perpendicular direction. The calculations show that the SrTaO2N layer is compressed along the ab-plane, while the SrTiO3 is elongated, thus favoring the formation of P4mm local environment on both sides of the interface, leading to net macroscopic polarization. The analysis of the local polarization as a function of the distance to the interface, for each individual 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 ab-plane. The resulting total polarization in the periodic array was ≈0.54 C/m2, which makes this type of arrangement suitable for microelectronic applications.