Developed during World War II to replace scarce mica in capacitors, BaTiO3 was shown by Arthur R. von Hippel in 1945 to exhibit ferroelectric switching and relative permittivity up to 7,000–15,000.
As it cools, its perovskite lattice transitions from paraelectric cubic above 120–130 °C through ferroelectric tetragonal, orthorhombic, and rhombohedral phases driven by off-center Ti4+ displacements.
It is the backbone dielectric of multilayer ceramic capacitors (MLCCs) and, when doped into a semiconductor, exhibits a positive temperature coefficient (PTC) of resistance used in self-regulating heaters.