Electron emission from ferroelectric ceramics with a special design patterned front electrode

Electron emission from a ceramic disk is due to spontaneous polarization switching induced by a high-voltage pulse applied to the surface electrodes. With a conventional front electrode, emission was erratic as a function of samples and decayed with shot number. On the contrary, when the front electrode consisted of a pattern of unconnected patches contained within a ring, emission was stable. The physics of the two configurations is investigated and a possible interpretation of the two different behaviors is given.