Carbon nitride thin film synthesized on iron buffer layers

Carbon nitride thin films were deposited on iron buffer layers by pulsed la ser deposition assisted with ion implantation. Two types of samples (A) and (B) were prepared with and without iron layers. Several techniques were us ed to study the properties of the samples. Scanning tunneling microscopy (S TM) was used to observe the surface structures of the samples. The differen ce in their surface morphologies was studied. The STM measurements also pro vided the relation between tunneling current and bias voltage to study the local density of states of the sample surface by calculating (dI/dV)/(I/V). Three band edges were observed from the calculated curve. Measurements by Raman and Fourier transform infrared (FTIR) spectra were carried out to stu dy the electronic properties of the samples. The Raman spectra showed the p resence of triply bonded carbon nitride bonds (C=N) in sample (A), while on ly single bonds were observed in sample (B) by FTIR spectra. The mechanical properties were studied by nanoindentation. Both hardness and bulk modulus of the thin films were measured. (C) 2000 American Institute of Physics. [ S0021-8979(00)06124-7].