Flexible polarisation rotation at the ferroelectric/metal interface as a seed for domain nucleation
by Xian-Kui Wei, Yurong Yang, Leo J. McGilly, Ludwig Feigl, Rafal E. Dunin-Borkowski, Chun-Lin Jia, Laurent Bellaiche, and Nava Setter
The absence of a realistic polarisation screening scenario at the pivotal ferroelectric-metal interface impedes the widespread application of low-dimensional ferroelectric heterostructures. Employing quantitative atom-resolved (scanning) transmission electron microscopy and first-principles calculations, the present study demonstrates that structural and chemical reconstruction universally lowers symmetry of the ferroelectric-metal interface. Irrespective of structural and strain mismatch, chemical termination and diffusion, polar catastrophe, and electrode type, the polarisation screening is executed by a flexible polarisation rotation at several-unit-cell-thick interfaces. By combining nanoscale and atomic-scale microscopy investigations, ex situ electric-field biasing experiments reveal that the monoclinically distorted interfaces may act as seeds to nucleate new domains during the polarisation switching process. These findings suggest that the long-standing fatigue issue is expected to be overcome by interface modification engineering at the monolayer scale.
Xian-Kui Wei, Yurong Yang, Leo J. McGilly, Ludwig Feigl, Rafal E. Dunin-Borkowski, Chun-Lin Jia, Laurent Bellaiche, and Nava Setter: Flexible polarisation rotation at the ferroelectric/metal interface as a seed for domain nucleation, Phys Rev B 98 (2018) 020102(R).