Study On Assembly And Field Emission Properties Of Carbon Nanotubes Onto Tips

The field emission properties of carbon nanotubes were studied by many scientists since it was found in 1995[1]. In this paper, the assembly of carbon nanotubes was handled by the low temperature sinter technology of nano-silver paste and the sample of carbon nanotubes was tested with the field emission equipment. It is a new kind of method for super spindle which is in study stage, used with gas field ion source (GFIS) which is a new type of focus ion beam technology.Nano- silver is widely used as one kind of nano materials. Especially, the melting point of nano- silver is 100℃or so, however, the melting point of common sliver is 960.5℃. Nano- silver low temperature sinter technology is research. The first part of the experiment belongs to nano-silver low temperature sinter technology methods development. After nano-silver powder is dissolved into organic impregnant such as acetal, ethanol, hexylic mellow and so on, the temperature split experiment is firstly going, the result shows that 200℃is the best sinter temperature, after that, the sinter time split experiment is on, the result shows that 90 min is the best sinter time. The nano- silver paste optimized experiment result: by quality fraction 65% nano-silver powder, 25% acetyl, 9% hexylic mellow and 1% cellulose is better prescription and its square resistance reach 0.022Ω/□.Generally, there are tow kinds of methods for the assembly of carbon nanotubes onto tips, one is physical assembly method and the other is chemical assembly method. This experiment belongs to chemical assembly method. Firstly, minim carbon nanotubes dissolve into the optimized nano- silver paste, then ultrasonic disperse is used, after manually assemble this kind of carbon nanotubes-sliver paste onto tips, the tips is sintered with 200℃and 90 min. All these tips are review by SEM and result show that one of 15 tips exist unique carbon nanotubes. The field emission equipment result show that polished stainless steel base can improve emission current from 89μA to 100μA, when the voltage of cathode is 2000 V.