Buscar

Estamos realizando la búsqueda. Por favor, espere...

Kittel law and domain formation mechanism in PbTiO3/SrTiO3 superlattices

Abstract: We report second-principles simulations on the structural and energetic properties of domains in (PbTiO3)n/(SrTiO3)n superlattices. For the explored layer thickness (n ranging between 8 and 16 unit cells) and lateral sizes of the domains, the most stable configuration corresponds to polar domains separated by a sequence of counter-rotating vortices (clockwise/counterclockwise) perpendicular to the stacking direction and acting as domain walls. The balance between the domain wall energy and the electrostatic energy yields to an optimal domain period ? that is proportional to the square root of the thickness of the PbTiO3 layer, following the Kittel law. For a given lateral size of the simulation box, suboptimal domain structures (with a width larger than the one predicted by the Kittel law) can be obtained in a metastable form. However, at finite temperature, molecular dynamics simulations show the spontaneous change of periodicity, which implies the formation of new domains whose generation is initiated by the nucleation of vortices and antivortices at the interface between the SrTiO3 and the PbTiO3 layers. The vortices progressively elongate and eventually annihilate with the antivortices yielding the formation of new domains to comply with the Kittel law via defect recombination.

 Autoría: Gómez-Ortiz F., Aramberri H., López J.M., García-Fernández P., Íñiguez J., Junquera J.,

 Fuente: Physical Review B, 2023, 107(17), 174102

 Editorial: American Physical Society

 Fecha de publicación: 01/05/2023

 Nº de páginas: 6

 Tipo de publicación: Artículo de Revista

 DOI: 10.1103/PhysRevB.107.174102

 ISSN: 1098-0121,1550-235X,2469-9950,2469-9969

 Proyecto español: PGC2018-096955-B-C41

 Url de la publicación: https://doi.org/10.1103/PhysRevB.107.174102

Autoría

FERNANDO GOMEZ ORTIZ

ARAMBERRI, HUGO