Field Emission Characteristics of Metal-doped Nano-diamond Cathode on Titanium Substrate

Field emission characteristics of metal-doped nano-diamond on titanium substrate were studied, wherein metals-Ti and Hf were mixed with nano-diamond separately, and cathode samples were prepared by electrophoresis. Then the structures and morphologies of cathode samples were characterized by SEM and XRD; finally, field emission tests were conducted. Results show that the morphology of 5 mg Ti-doped sample is more uniform and dense, but the morphologies of Hf-doped samples become worse. Meanwhile, compared with the undoped sample, field emission characteristics of Ti-doped samples improve, while those of Hf-doped samples decrease. From the comparison between Ti-doped samples, it is found that the amount of Ti mixed with nano-diamond should not be too much; a moderate amount of Ti can improve field emission characteristics of nano-diamond on Ti substrate. It is determined by the nature of metal Ti and Hf, which influences the bonding reaction between nano-diamond and substrate Ti, thus affecting, field emission characteristics of doped nano-diamond on Ti substrate.