Simulation of material properties of amorphous carbon nitride with different nitrogen concentrations

A theoretical model is proposed to simulate the structures of amorphous car bon nitride. An understanding of amorphous carbon nitride structures and pr operties is helpful for the synthesis and applications of this novel materi al. The influence of the nitrogen concentration on the cohesive energy, bul k modulus, and vibration density spectra was studied. An expression for the total cohesive energy of an atom group was established. The material struc ture can be simulated by minimizing the total energy of the atoms in the gr oup. From the simulated structure of the material, many properties can be p redicted. The results show that either high or low nitrogen concentrations in the carbon nitride led to a high bulk modulus. The vibrational spectra o f carbon and nitrogen atoms depend on the nitrogen concentration. This theo retical model may help to identify an appropriate process to grow hard film s with expected properties. (C) 1999 American Institute of Physics. [S0021- 8979(99)08222-5].