Lifetime of ferroelectric cathodes

We study the lifetime and emission properties of ferroelectric cathodes mad e 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 structur e of the emitting surface of the samples were studied by scanning electron microscopy. It was found that the lifetime of the tested cathodes depends s trongly on their composition as well as on the parameters of the driving pu lse. Namely, the driving pulse causes a substantial damage in lead-zirconiu m-titanate-type samples and a structural change in the surface of barium-ti tanate-type samples. In addition, fast deterioration was found in the emiss ion properties of the tested cathodes along with increasing number of drivi ng pulses. We discuss our results within the framework of the incomplete su rface discharge model. (C) 2001 American Institute of Physics.