Fig. 3: Formation of reversed domains and the temperature-dependent polarization switching in Td-WTe2.
From: Sub-nanosecond polarization switching with anomalous kinetics in vdW ferroelectric WTe2
a Schematic illustration of a reversed domain in Td-WTe2, highlighting three types of domain walls: stretched (i), twisted (ii), and bent (iii). The arrows represent local polarization directions. In the stretched domain wall, atomic distances of the upper layer increase. In the bent domain wall, the upper layer bends due to the opposite sliding of neighboring regions. b Influence of temperature on the polarization and energy barriers between opposite polarization states in Td-WTe2, BN, and PbTiO3. For WTe2, increasing temperature reduces polarization and slightly elevates the intrinsic barrier, whereas BN and PbTiO3 retain stable polarization and intrinsic barriers. Here, δ denotes the barrier without an external field. The inset shows how temperature affects the electron distribution near the Fermi level, controlled by the smearing parameter σ. c Under an external electric field E, the switching barrier is defined as ∆ = δ−E · P. The blue line represents low temperature, the red line high temperature, and the black line the intrinsic barrier. The charge density difference demonstrates charge transfer between layers during the ferroelectric phase transition.
