Fabrication and characterization of pressed Y2O3 doped Ba-W dispenser cathode

A new kind of pressed Y
₂
O
₃
doped Ba-W dispenser cathodes are prepared by a sol-gel method combined with high temperature sintering in dry hydrogen atmosphere. The results show that the growth of the grains is hampered by the pinning effect of Y
₂
O
₃
distributing uniformly on the surfaces of tungsten particles, resulting in the formation of small grain size. It is found that Y
₂
O
₃
improves the secondary electron emission property, i.e., the secondary emission yield increases with the increase of Y
₂
O
₃
content in the samples. The maximum secondary emission yield δ
_max
of the cathode with 15% amount of Y
₂
O
₃
can reach 2.92. Furthermore, the cathode shows a certain thermionic emission performance. The zero field emission current density J
₀
of 4.18A/cm has reached at 1050
^o
C
_b
for this kind of cathode after being activated at 1200
^o
Cb, which are much higher than that of rare earth oxide doped molybdenum (REO-Mo) cathode reported in the previous work.