负脉冲激励下PLZST电子发射特征及发射机理研究

Characteristics of electron emission from La-doped Pb(Zr,Sn,Ti)O_3 antiferroelectric cathode under negative triggering pulse

采用固态烧结工艺制备了位于反铁电/铁电相界附近的掺镧锆锡钛酸铅(PLZST)反铁电陶瓷样品.采用该样品作为阴极材料,研究了其在负脉冲激励电场下的电子发射行为.负脉冲激励下,0.5mm厚PLZST反铁电陶瓷圆片发射阈值电压为500V;当激励电压为500V,抽取电压为3.5kV时,得到690A发射电流.结果表明,PLZST反铁电陶瓷发射阈值电压低,发射电流大,即使激励电场低于陶瓷的正向开关电场,仍能得到强发射电流.最后,讨论了PLZST反铁电陶瓷在负脉冲激励下电子发射内在机制.

An antiferroelectric cathode material, lanthanum-doped lead zirconate stannate titanate （PLZST） located in the vicinity of antiferro-ferroelectric phase boundary, was prepared by solid state calcination method. The electron emission property of the novel antiferroelectric cathode under the negative triggering voltage pulses was investigated. The emission threshold value voltage from PLZST with 0.5 mm width under negative triggering pulses was 500 V. For negative triggering voltage of 500 V and extraction voltage of 3.5 kV, a large emission current of 690 A was obtained. It was indicated that the emission threshold value voltage was low and the emission current was large. Even when the triggering voltage was lower than the positive switch electric field, strong emission current can be obtained from PLZST. Finally, the mechanism of electron emission of PLZST under negative triggering pulses was discussed.