Nanocrystalline boron nitride (BN) with a whisker-like morphology has been
synthesized from the reaction of KBH4 and NH4Cl at a temperature of 650 deg
rees C and a pressure of about 22 MPa. The pressure is much lower than that
of previous routes and the yield of nanocrystalline BN reached 70%. X-ray
powder diffraction pattern indicated the coexistence of two structures of B
N: hexagonal and cubic. Fourier transformation infrared spectroscopy was us
ed to distinguish the sp(2)-bonded hexagonal and sp(3)-bonded cubic phase.
X-ray photoelectron spectra analysis gave the average composition of B1.01N
. (C) 1999 Academic Press.