The image (in optical microscope) of the domain walls (vertical dark stripes) in ferroelectric BaTiO3. (dark spots are dirt). When the strong electric field is applied on this material, the ferroelectric polarization is switched from the one (let's call it "up") to another ("down") polarization. The ferroelectric cycling is shown on the left graph. Video (7 seconds) shows the disappearance of domain walls, i.e. switching of ferroelectric polarization when the applied voltage overcomes the coercivity field (here around V=100V).
