Synthetic approaches to borocarbonitrides, BCxN (x=1-2)

In order to synthesize borocarbonitrides of the general formula BCxN where x varies between 1 and 2, we have carried out high-temperature gas phase reaction of BBr3 with a mixture of ethylene and ammonia. The composition of the product was close to BC1.6N as shown by x-ray photon spectroscopy (XPS) and electron energy loss spectroscopy (EELS). The products were further characterized by infrared, Raman and other spectroscopic techniques. The borocarbonitrides obtained from the gas phase reaction have low surface areas, in contrast to those of similar compositions prepared by the urea method. First principles calculations show that the most stable structures of the compositions BCN and BC2N contain BN-rich and carbon-rich domains where BN3 and NB3 units are present. (C) 2011 Elsevier Inc. All rights reserved.