We measured firstand second-order Raman scattering in cubic and hexagonal boron nitride using excitation energies in the visible and in the UV. The nonresonant first-order Raman susceptibilities for cubic and hexagonal BN are 1 and 10 Å2, respectively. Raman scattering is thus very powerful in detecting the hexagonal phase in mixed thin boron nitride films. In cubic BN the constant Raman sucsep...

* Presented as Paper IEPC-01-39 at the 27 International Electric Propulsion Conference, Pasadena, CA, 15-19 October 2001. † Copyright © 2001 by Stanford University. Published by the Electric Rocket Propulsion Society with permission. A preliminary assessment of the sputter resistance of polycrystalline diamond plates against xenon ion bombardment is reported, and first studies of integrating di...

Single-walled boron nitride nanotubes are chosen as model reactants, and (10,0) and (6,6) are chosen as representatives of armchair and zigzag nanotubes, respectively, to study the interaction of carbenes of the type :CX2. It is found that, contrary to the case of carbon nanotubes, boron nitride tubes, particularly armchair BNNTs, do not show a propensity for cyclopropane ring formation. The SW...

An efficient method for purification of Yard-Glass Shaped Boron Nitride NanoTubes (YG-BNNTs) fabricated via a Chemical Vapour Reaction (CVR) route has been developed. Impurities including carbon, Boron Nitride (BN), and Fe species in the pristine YG-BNNT sample are removed by a combined physical and chemical procedure which involv<e...

: A theory is presented for the modification of bandgaps in atomically thin boron nitride (BN) by attractive interactions mediated through phonons in a polarizable substrate, or in the BN plane. Gap equations are solved, and gap enhancements are found to range up to 70% for dimensionless electron-phonon coupling λ =1, indicating that a proportion of the measured BN bandgap may have a phonon ori...

In this work the fracture toughness of epoxy resin has been improved through the addition of low loading of single part and hybrid nanofiller materials. Functionalised multi-walled carbon nanotubes (f-MWCNTs) was used as single filler, increased the critical strain energy release rate, GIC, by 57% compared to the neat epoxy, at only 0.1 wt% filler content. Importantly, no degradation in the ten...

Multiwall carbon nanotube (MWNT) reinforced silicon nitride ceramics matrix composites have been prepared. The hot isostatic press (HIP)-sintering method was used for composite processing. Bending strength and elastic modulus of MWNT-silicon nitride composites showed a considerable improvement compared to matrices with added carbon fiber, carbon black or graphite. However, the silicon nitride s...