A ferroelectric opening switch is enabled by controlled polarization switching via nucleation in a ferroelectric material, such as BaTiO3, Pb(Zr,Ti)O3, LiNbO3, LiTaO3, or variants thereof. For example, nucleation sites can be provided by mechanical seeding, grain boundaries, or optical illumination. The invention can be used as an opening switch in large scale pulsed-power systems. However, the switch can also be used in compact pulsed-power systems (e.g., as drivers for high power microwave systems), as passive fault limiters for high voltage dc (HVDC) systems, and/or in other high power applications.