Catálogo de publicaciones - tesis
Título de Acceso Abierto
Modelado computacional de películas delgadas de óxidos ferroeléctricos: efectos de un gradiente de deformación y su interacción con nanocintas de grafeno
Gustavo Daniel Belletti Silvia Tinte Ariel Dobry Gabriela Fernanda Cabeza Pablo Bolcatto Segio Daniel Dalosto
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Resumen/Descripción – provisto por el repositorio digital
In this thesis, we theoretically study first the microscopic properties of the ferroelectric material PbTiO3 in free and ultrathin films. Using an atomistic core-shell model through classical Molecular Dynamics simulations, we find that the generated structures of ferroelectric domains depend on the film thickness. For thicknesses smaller than 80 Å, the local electrical polarizations are arranged in closed flows forming vortices. For greater thicknesses, we observe structures of the Landau-Lifshitz type. We then analyze the polarization response to a local and compressive strain gradient on the PbTiO3 film. By gradually increasing the gradient value, we describe the evolution of the local polarization perpendicular to the surface until the switching is reached. In the second part, using first-principles calculations we study how the electrical and magnetic properties of graphene nanoribbons change when they are supported on PbTiO3 films. First, a nanoribbon adsorbed on a PbTiO3 film in a monodomain configuration, where a charge redistribution takes place at the interface and an electronic doping is present in the graphene nanoribbon depending on the polarization direction of the ferroelectric material, which also induces the close of the electronic gap but without breaking the spin degeneration. Finally, we analyze the effect on a graphene nanoribbon adsorbed on different regions at the surface of a PbTiO3 ultrathin film with polydomains. Our results suggest that if a graphene nanoribbon were spatially displaced above ferroelectric domains it would be possible to tune not only the nanoribbon electronic doping but also the degeneration of its electronic states.Palabras clave – provistas por el repositorio digital
Ferroelectric; Lead titanate; Graphene nanoribbon; Strain gradient; Abinitio; Molecular dynamics; Ferroeléctrico; Titanato de plomo; Nanocinta de grafeno; Gradiente de deformación; Ab-initio; Dinámica molecular
Disponibilidad
| Institución detectada | Año de publicación | Navegá | Descargá | Solicitá |
|---|---|---|---|---|
| No requiere | 2016 | Biblioteca Virtual de la Universidad Nacional del Litoral (SNRD) |
|
Información
Tipo de recurso:
tesis
Idiomas de la publicación
- español castellano
País de edición
Argentina
Fecha de publicación
2016-03-23
