Ferroelectric Switching
Ferroelectrics possess a spontaneous polarization switchable by an applied electric field. The P-E hysteresis loop arises from domain nucleation and growth: as the field ramps past the coercive field E_c, antiparallel domains nucleate and sweep across the crystal.
The Landau–Khalatnikov equation governs dynamics: γ dP/dt = −∂F/∂P + E, where F = aP² + bP⁴ is a double-well free energy. Disorder (quenched randomness in domain pinning) broadens the loop and reduces the remnant polarization.
Landau theory
double-well potential
domain nucleation
BaTiO₃ / PZT