Can I read Strain-gradient-induced Switching of Nanoscale Domains in Free-standing Ultrathin Films on EtoBox?

Strain-gradient-induced Switching of Nanoscale Domains in Free-standing Ultrathin Films by Belletti, G. D.; Dalosto, S. D.; Tinte, Silvia is a scholarly article available to read on EtoBox.

What is Strain-gradient-induced Switching of Nanoscale Domains in Free-standing Ultrathin Films about?

We report first-principle atomistic simulations on the effect of local strain gradients on the nanoscale domain morphology of free-standing PbTiO$_3$ ultrathin films. First, the ferroelectric properties of free films at the atomic level are reviewed. For the explored thicknesses (10 to 23 unit cells), we find flux-closure domain structures whose morphology is thickness dependent. A critical value of 20 unit cells is observed: thinner films show structures with 90$^\circ$ domain loops, whereas thicker ones develop, in addition, 180$^\circ$ domain walls, giving rise to structures of the Landau-Lifshitz type. When a local and compressive strain gradient at the top surface is imposed, the gradient is able to switch the polarization of the downward domains, but not to the opposite ones. The evolution of the domain pattern as a function of the strain gradient strength consequently depends on the film thickness. Our simulations indicate that in thinner films, first the 90$^\circ$ domain loops migrate towards the strain-gradient region, and then the polarization in that zone is gradually switched. In thicker films, instead, the switching in the strain-gradient region is progressive, not in

Author

Belletti, G. D.; Dalosto, S. D.; Tinte, Silvia

Published

2014

Language

EN