The effect of the surface microstructures on the emission characteristics of ferroelectric cathode

Summary form only given. The pulsed electron source using a ferroelectric cathode can easily produce an electron beam of high current density with relatively low driving voltage. The originally proposed mechanism in which the screening electrons captured on the surface of the ferroelectric cathode were pulled away by coulomb potential of spontaneous polarization is not adequate to explain the experimental data. It has been shown that the surface plasma triggered by a reversal of spontaneous polarization is crucial for the electron emission (Shur et al., 1997). Microscopic studies have been conducted from a point of view on the mechanism of ferroelectric electron emission (FEE) under the influence of surface microstructures (Miyake et al., 1997, Zhang et al., 1998). Commercially available disk shaped PZT ceramics of 500 /spl mu/m thickness are used as cathodes. The gold electrodes were deposited; fully solid on the bottom surface and grid electrode of 100 /spl mu/m width and 300 /spl mu/m separations on the top surface. Negative pulsed voltage with the rise time of 100 ns is applied to the bottom surface. The luminescence is always observed whenever the electron emission occurs. The luminescence points are mostly found not on the edge of the grid electrode but on the cutoff points of the grid electrode. After the several shots, many micro cracks are formed near the cutoff points.