Instruments and methods of investigation

Electron emission from ferroelectric plasma cathodes

Lebedev Physical Institute, Russian Academy of Sciences, Leninsky prosp. 53, Moscow, 119991, Russian Federation

Recent and not so recent experimental data are analyzed to show that the reason for strong electron emission from dielectric cathodes is the incomplete discharge occurring on the dielectric surface due to the electric field there being tangentially nonzero. The places of origin of such discharges are the metal-dielectric-vacuum triple junctions (TJs). As the discharge plasma moves over the surface of the dielectric electrode, the bias current arises, and an electric microexplosion occurs at a TJ. If the number of TJs is large, as it is for a metal grid held tightly to a ferroelectric, electron currents of up to 104 A with densities of more than 102 A cm-2 can be achieved. A surface discharge is initiated by applying a triggering pulse to the metal substrate deposited beforehand onto the opposite side of the ferroelectric. If this pulse leads the accelerating voltage pulse, the electron current is many times the Child-Langmuir current. The reason for the ferroelectric effect is the large permittivity (ε > 103) of the materials used (BaTiO3, PLZT, PZT). Although these devices have come to be known as ferroelectric cathodes, we believe ferroelectric plasma cathodes would be a better term to use to emphasize the key role of plasma effects.

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Fulltext is also available at DOI: 10.1070/PU2008v051n01ABEH006426
PACS: 52.80.−s, 84.70.+p, 85.45.−w (all)
DOI: 10.1070/PU2008v051n01ABEH006426
Citation: Mesyats G A "Electron emission from ferroelectric plasma cathodes" Phys. Usp. 51 79–100 (2008)
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Оригинал: Месяц Г А «Электронная эмиссия из сегнетоэлектрических плазменных катодов» УФН 178 85–108 (2008); DOI: 10.3367/UFNr.0178.200801e.0085

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