铁电阴极材料压电系数在电子发射过程中的实验规律

Experimental regularity of piezoelectric coefficient inthe electron emission with ferroelectric materials

作为一种新型功能材料,铁电阴极材料的研究日益受人们重视。对铁电材料进行电子发射试验时,偶然观测到材料压电系数随着电子发射次数的增多,其数值大小渐次先由高降低至零,然后又开始反向增大并逐渐稳定于某一绝对值,该绝对值略小于预极化初始值,而在这变化过程中,材料的电子发射电流密度基本恒定。对此进行重复验证以及系统考察发现,压电系数的这种变化规律,为铁电材料电子发射时所普遍遵循,这为铁电电子发射的机理研究探索又提供了一种新的实验现象。

The ferroelectric cathode material is a new kind of functional material. A new electron emission phenomena was observed by chance. With the increase of emission times, the piezoelectric coefficient decreased to zero firstly and then gradually approached to a given inverse value, whose absolute value was less than that of the initial value. Surprisingly, it was found that the current emission density had not changed during the course of the change of the piezoelectric coefficient. It is found that the experiment is repeatable. It is difficult to explain the observed phenomena using the existing electron emission theory.