High-current-density electron emission from lead zirconium titanate ferroelectric disc under application of short-duration high-voltage pulses

High-current-density pulsed-electron emission is observed from a poled lead zirconium titanate (PZT, Zr/Ti:53/47) ferroelectric ceramic disc on application of short-duration (/spl sim/6 ns) negative high-voltage (/spl sim/4 kV) pulses. Electron-emission pulses with a peak current density /spl sim/400--450 A/cm/sup 2/ and a full-width at half-maximum (FWHM) duration of /spl sim/200--250 ns were recorded in the presence of a dc extraction field. These are comparable to the various earlier results obtained using excitation pulses of duration comparable to the polarization switching time (/spl ges/100 ns). Self-emission of electrons with a current density of /spl sim/20--30 A/cm/sup 2/ was also observed. The experimental observations indicate occurrence of partial polarization reversal in the ferroelectric sample followed by plasma formation on the surface.