Pressure dependence and current stability of field emission from carbon nanotubes on porous alumina

Carbon nanotubes are synthesized by CVD using source precursors of metallocene related structures both on commercial and home made electrochemically etched porous alumina membranes of different thickness (60-200 μm) and pore diameter (50-200 nm). AFM, SEM, EDX and TEM investigations showed that the tubular structures formed within the pores of the alumina membranes are composed of pyrolytic carbon in which nanoscaled metallic particles are incorporated. Long-term processing effects in the pressure range resulted in both irreversible degradation and reversible activation of some emitters.