On the metastable phase in BaTiO3 single crystals

An intermediate structural phase was found between the cubic and tetragonal phases during investigations of dielectric dispersion of highly perfect BaTiO3 single crystals in temperature range 121 degrees C -> 80 degrees C. The phase was identified as a metastable phase, typical for the first-order phase transitions. It is suggested that the phase is a common property of BaTiO3 single crystals. The manifestation of the metastable phase is usually excluded by growth defects and defects introduced during preparation and measurements which create nucleation centers of a low-temperature phase.