Field-excited electron emission from (1-y)Pb(Mg1/3Nb2/3)O-3-yPbTiO(3) ceramic

Electron emission from a (1-y)Pb(Mg1/3Nb2/3)O3-yPbTiO3 (PMN-PT) ferroelectric ceramic plate has been observed in vacuum by applying a pair of bipolar pulse voltages. The emission is observed even at temperatures above the Curie temperature, as is that of a lead-zirconate-titanate (PZT) ceramic plate. The amount of emitted charge from PMN-PT ceramic is about 5 times larger than that from PZT ceramic, and increases with increasing pulse width. Furthermore, the temperature dependence of the emitted charge suggests that the amount of emitted charge depends strongly on the dielectric constant of the sample. It is considered that the emission is induced by abrupt change of dielectric Bur as well as the polarization reversal.