A THEORETICAL TREATMENT OF ELECTRIC BREAKDOWN IN BARIUM TITANATE
E.G. Franzak · 1958
A method is developed based on an essentially rigid ion hypothesis fer the calculation of the electric breakdown field strength in ionic crystals. The basic mechanism responsible for breakdown is assumed to be an electron avalanche effect, and the theory rests on a calculation of the rate at which a conduction electron gains energy from the applied field and loses energy to the lattice vibrations. To this end, the effect of the lattice vibrations is treated by means of a time-dependeat perturbation theory. The ionic nature of barium titanate is assumed, and a calculation of the breakdown field strength is made for a single crystal at 150 C in the cubic nonferroelectric phase. A value of 16.9 x 101 volts/cm is obtained. The limitations and assumptions of the theory are discussed, and suggestions for improvement are made. (auth)