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...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | Argentina |
| Institución: | Universidad Nacional de La Plata |
| Repositorio: | SEDICI (UNLP) |
| Idioma: | inglés |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/124904 |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/124904 |
| Access Level: | acceso abierto |
| Palabra clave: | Ingeniería Ciencias Exactas Física ab initio calculations ferroelectrics heterostructures |
| Sumario: | 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 <i>ab</i>-plane, while the SrTiO₃ is elongated, thus favoring the formation of <i>P</i>4<i>mm</i> 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 <i>ab</i>-plane. The resulting total polarization in the periodic array was ≈ 0.54 C m⁻², which makes this type of arrangement suitable for microelectronic applications. |
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