Elsevier, Carbon, 5(50), p. 2037-2044, 2012
DOI: 10.1016/j.carbon.2012.01.023
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A new cathode for cold-field emission gun using a pyrolytic carbon-cone supported onto a carbon nanotube as the electron emitting tip has been developed. This tip was mounted in a TEM using a FIB based method, and the brightness measured under real operating conditions is five times better than obtained with a standard tungsten tip. Its use overcomes the many technical difficulties which have dogged the use of carbon nanotube-based tips as proposed replacements for tungsten tips. The resulting properties of the final CFEG exhibit a very good energy spread of 0.32 eV, a reduced brightness of 1.6 × 109 A m−2 sr−1 V−1 and a very good long-term stability with a current damping less than 16% per hour.