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Multistep polarization switching on orthorhombic domain walls: a molecular dynamic study
- Date: 07.02.2023
- Place: Fundamental Physics of Ferroelectrics, Colarado School of Mines, US
Ferroelectric switching is the key property for a wide range of applications, ranging from actuators to memory devices. In spite of its fundamental relevance the ferroelectric switching process and its coupling to the microstructure is still not fully understood .
In this contribution we combine density functional theory and molecular dynamics simulations to study the microscopic processes governing the field-induced domain wall motion in (Sr,Ba)TiO3
Excitingly, we find that fast field changes may boost the wall velocity by non- equilibrium switching of local dipoles , see Figures (a--c). With time these dipoles switch back and the domain wall motion reaches its steady state. The dynamics of the wall can be considerably modified by point defects and inhomogeneities. For example, Sr-rich regions strained by a surrounding Ba-rich matrix increase the energy barrier for the wall motion, see Figures (d)—(e).
In the orthorhombic phase, local non-180o switching of dipoles on the traveling walls results in transient local Bloch type walls and dipole vortices.
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