  Electric-polarization reversibility in nano-ferroelectric structures renders
them as a convenient platform for exploring phase transitions and developing
energy-efficient switching devices. However, the fundamental question of how
ferroic domains switch, i.e. how the polarization changes from one state to
another, is yet to be answered fully. There are contradicting models and a wide
body of accumulated data which disagree as to whether the switching requires
domain nucleation. Moreover, ferroelectric domains switch under electric fields
that are supposedly too weak to form nucleation sites, indicating that the
level of disorder seen in real systems plays an important role. This
longstanding so-called Landauer's paradox is the ferroelectric equivalent to
the absence of raindrop formation in a dust-free vacuum, leading to
supersaturated vapors that cannot exist otherwise, e.g. in spinodal
decompositions or inhomogeneous nucleation environments. Here we show that
polarization switching in ferroelectric-ferroelastic systems comprises domain
types that differ by symmetry, lengthscale and switching energy. These domains
switch simultaneously thanks to intermediate-range order of organized pinning
sites, supporting the previously-unexplained coexistence of
nucleation-and-growth and nucleation-frustrated mechanisms. Our treatment is
applicable to other Kolmogorov-Avrami systems with multi-scale phase
transitions. Finally, we demonstrate augmented electromechanical coupling based
on the collective motion of pinning sites, which is promising for nano
electro-mechanical and low-power switching devices.
