@article{10902/32040,
year = {2023},
month = {5},
url = {https://hdl.handle.net/10902/32040},
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 ω 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.},
organization = {F.G.-O., P.G.-F., and J.J. acknowledge financial support from Grant No. PGC2018-096955-B-C41 funded by MCIN/AEI/10.13039/501100011033 and by ERDF "A way of making Europe" by the European Union. F.G.-O. acknowledges financial support from Grant No. FPU18/04661 funded by MCIN/AEI/ 10.13039/501100011033. J.M.L. was supported by Grant No. PID2021-125543NB-I00 funded by MCIN/AEI/10.13039/501100011033/ and by ERDF "A way of making Europe" by the European Union. H.A. and J.I. were funded by the Luxembourg National Research Fund through Grant No. C21/MS/15799044/FERRODYNAMICS.},
publisher = {American Physical Society},
publisher = {Physical Review B, 2023, 107(17), 174102},
title = {Kittel law and domain formation mechanism in PbTiO₃/SrTiO₃ superlattices},
author = {Gómez Ortiz, Fernando and Aramberri, Hugo and López Martín, Juan Manuel and García Fernández, Pablo (físico) and Íñiguez, Jorge and Junquera Quintana, Francisco Javier},
}