TARGET HOLDERS, MULTIPLE INCIDENCE ANGLE, AND MULTIZONE HEATING FOR BNNT SYNTHESIS

摘要

In the synthesis of boron nitride nanotubes (BNNTs) via high temperature, high pressure methods, a boron feedstock may be elevated above its melting point in a nitrogen environment at an elevated pressure. Methods and apparatus for supporting the boron feedstock and subsequent boron melt are described that enhance BNNT synthesis. A target holder having a boron nitride interface layer thermally insulates the target holder from the boron melt. Using one or more lasers as a heat source, mirrors may be positioned to reflect and control the distribution of heat in the chamber. The flow of nitrogen gas in the chamber may be heated and controlled through heating elements and flow control baffles to enhance BNNT formation. Cooling systems and baffle elements may provide additional control of the BNNT production process.

主权项

1. A method for synthesizing boron nitride nanotubes, the method comprising:
positioning an initial boron feedstock on a target holder in a chamber; flowing nitrogen gas through the chamber at an elevated pressure; heating the initial boron feedstock to form a boron melt; and introducing a boron nitride interface layer between the boron melt and the target holder; wherein the boron nitride layer is formed by cooling the target holder to create a temperature gradient between the boron melt and the target holder.