Material dependence of ferroelectric emission under strong accelerating field

We have studied emission characteristics of a PZT ferroelectric cathode under influence of a strong accelerating field using two kinds of PZT materials, LZT-2 and APC850, with the same cathode geometry. The perveances of the electron guns differ by more than 100%. The difference of the emitted electron is found to be related to the difference of frequency characteristics of the materials, which implies that the electron emission is possibly caused by the local domain oscillation in the close vicinity of vacuum-ferroelectric-metal triple-junction. The experimental results provide a key-point, which may lead to a more complete understanding of electron emission from ferroelectric materials.