Composition and bonding structure of boron nitride B_(1-x)N_x thin films grown by ion-beam assisted evaporation

摘要

We present a detailed study of B_(1-x)N_x (0 < x < 0.6) films synthesized at room temperature by N2+ ion-beam assisted evaporation of boron. The atom-ion ratio was related to the final boron concentration as determined by X-ray energy dispersive spectroscopy (XEDS), and to the bonding structure explored by infrared (IR) and X-ray absorption near-edge structure (XANES) spectroscopies. IR and XANES revealed that N-rich boron nitrides had a graphite-like structure with embedded nitrogen molecules, while B-rich boron nitrides consisted of different ratios of B _(13)N_2/h-BN phases. Our spectroscopic results indicate that this B_(13)N_2 structure is made of B_(12) icosahedral units linked by N-B-N linear chains.