The dc breakdown field has been measured for ceramic BaTi${\mathrm{O}}_3$ as a function of the ambient temperatures. The breakdown field shows, in general, a temperature dependence of the thermal breakdown type where the breakdown field decreases as the temperature is increased. However, in addition to this general behavior, the breakdown field dips down strongly and shows minima at the critical temperatures of the phase transformations. This seems to indicate a process of polarization breakdown, and is most pronounced near the orthorhombic-tetragonal transition temperatures.

• Received 28 July 1958

DOI:https://doi.org/10.1103/PhysRev.113.456