sp/sup 2/-sp/sup 3/ carbon bulk composite material for cold electron emitters

Carbon bulk composite materials are promising candidates for cold emission cathodes. Emission properties of sp/sup 2/-sp/sup 3/ carbon bulk composite material were studied, with the share of sp/sup 2/ and sp/sup 3/ phase content of carbon being varied. Emission currents of /spl sim/2 mA/cm/sup 2/ at an electric field of /spl sim/18 V//spl mu/m were obtained.