A microstructural study of boron nitride films grown by ion-assisted pulsed laser deposition is
presented. Fourier transform infrired spectroscopy, electron-energy-loss spectroscopy, and
electron-diffraction measurements indicate that within the ion-irradiated region on the
substrate, the film consists of a high fraction of the cubi& phase (cBN) with a small amount of
the turbostratic phase; outside the irradiated region, only the turbostratic phase is detected.
Conventional and high-resolution electron microscopic observations show that the cBN is in …