Lifetime of ferroelectric cathodes

We study the lifetime and emission properties of ferroelectric cathodes made of perovskites with the ABO(3) composition. To excite electron emission, we applied negative driving pulses with different amplitudes and durations to the rear electrode of the ferroelectric cathodes. The composition of the samples before and after the experiments was checked by energy dispersive spectroscopy and by Auger electron spectroscopy. The image and the structure of the emitting surface of the samples were studied by scanning electron microscopy. It was found that the lifetime of the tested cathodes depends strongly on their composition as well as on the parameters of the driving pulse. Namely, the driving pulse causes a substantial damage in lead-zirconium-titanate-type samples and a structural change in the surface of barium-titanate-type samples. In addition, fast deterioration was found in the emission properties of the tested cathodes along with increasing number of driving pulses. We discuss our results within the framework of the incomplete surface discharge model. (C) 2001 American Institute of Physics.