Title :
Electron emission from ferroelectric ceramics
Author :
Ivers, J.D. ; Advani, R. ; Nation, J.A. ; Schachter, L.
Author_Institution :
Sch. of Electr. Eng., Cornell Univ., Ithaca, NY, USA
Abstract :
The results of experiments on the emission of electrons from ferroelectrics are reported. A sample of PZT is pulsed to reverse the direction of the spontaneous polarization within the material. This releases the surface charge accumulated on the ferroelectric, which is needed to reduce the external electric field to a low value. Surface charge densities may amount to about 0.5 C/m/sup 2/. In these experiments, the emitted electron current density reaches a peak value of up to 70 A/cm/sup 2/ for a diode gap of 4 mm and an extraction voltage of 500 V. Beam current densities exceed the Child-Langmuir law for space-charge-limited emission by factors of up to 400. Measurements showing the dependence of the emission on the diode voltage and spacing are presented. The authors´ understanding of the emission process and its limitations are summarized.<>
Keywords :
ceramics; electron emission; electron sources; ferroelectric materials; lead compounds; space charge; 4 mm; 500 V; PZT; PbZrO3TiO3; electron emission; emitted electron current density; ferroelectric ceramics; space-charge-limited emission; spontaneous polarization; surface charge; Cathodes; Ceramics; Current density; Diodes; Electron emission; Ferroelectric materials; Polarization; Silver; Transmission lines; Voltage;
Conference_Titel :
Particle Accelerator Conference, 1991. Accelerator Science and Technology., Conference Record of the 1991 IEEE
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-0135-8
DOI :
10.1109/PAC.1991.164880
