Structure and optical properties of nanosized boron nitride obtained in optical furnace without catalysts

Abstract

A structure, phase composition and behaviour of optical absorption of boron nitride produced in the high-power optical furnace with xenon sources of exposure in nitrogen environment are studied. As shown, under the experimental conditions, the phase composition of the obtained material is a mixture of hexagonal BN, two tetragonal phases with the increased boron content (В51,2N and В25N), and amorphous phase. There are three linear sections on the dependence of the absorption-coefficient square on photon energy of incident light in the region of absorption band gap. They correspond to band gaps of 3.0, 3.8 and 4.5 eV. The features of spectral dependence of optical absorption can be explained by absorption by corresponding phases: tetragonal В51,2N (3.0 eV), В25N (3.8 eV) and h-BN (4.5 eV).