Hexagonal Boron Nitride from a Borazine Precursor for Coating of SiBNC Fibers using a Continuous Atmospheric Pressure CVD Process

Abstract

The aim of this work is the coating of SiBNC fibers with hexagonal boron nitride (h-BN) for ceramic composite applications. h-BN is deposited from borazine in a vertical, hot-wall, atmospheric pressure (AP)CVD system. The effects of deposition parameters (e.g., temperatures, reactant concentrations, and gas velocity) on the deposition rates are investigated using Si (100) substrates statically placed at various positions in the reactor. The highest deposition rates are observed at 1090 8C. It is found that ammonia is necessary for a satisfying coating deposition and for low oxygen incorporation, though high concentrations decreased the deposition rate. The coating structures are characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Based on the results of static h-BN deposition on Si substrates, h-BN is continuously and homogenously coated on SiBNC multifilaments with a fiber draw speed of 5 m h À1. The thickness of the coating on SiBNC fibers is 180-200 nm as measured by SEM. The h-BN coatings from our experiments have no influence on the mechanical strength of the SiBNC fibers.

Nanostructured and architectured boron nitride from boron, nitrogen and hydrogen-containing molecular and polymeric precursors

“…It should be mentioned that Paffett et al were the first to report the decomposition of BZ on Pt(1 1 1) and Ru(0 0 1 1) surfaces below 1000 8C [90]. The strong interest of BZ as a thin film precursor was also proved on other substrates such as Si(1 0 0) and SiBNC fibers with no decrease in their mechanical strength [91]. However, the interest of AB and BZ to prepare 3D BN is problematic because of the relatively high cumulative weight loss occurring during pyrolysis which imposes important volume shrinkage.…”

2D III‐Nitride Materials: Properties, Growth, and Applications

“…[ 181–185 ] The common precursors and substrates used to develop h‐BN system by CVD are summarized in Table 6 . [ 180,186–213 ]…”

Boron nitride ceramics from molecular precursors: synthesis, properties and applications

“…95 The strong interest of BZ as a film precursor was also proved in other substrates such as Si(100) and SiBCN fibers with no decrease in their mechanical strength. 96 Recently, the structure of epitaxially grown h-BN on Ir (111) was investigated by CVD using BZ. 97 By photoelectron diffraction spectroscopy, the authors demonstrated that a single-domain h-BN monolayer can be synthesized by a cyclic dose of BZ onto a metal substrate at room temperature followed by annealing at T = 1000 °C.…”