Crystalline carbon nitride was easily synthesized from CN radicals pre
pared by the reaction between N atoms and a graphite rod anode in the
argon-nitrogen plasma arc at atmospheric pressure. The deposits on Si
(111) wafer substrate were identified as beta-C3N4 by the x-ray diffra
ction method, and the C-N bond was detected in the deposit by infrared
(IR) spectroscopy and x-ray photoelectron spectroscopy (XPS). The exi
stence of sp3 orbital on the C atom in C3N4 is presumed from the XPS s
pectra of the valence band of the deposit.