We report results from cathodoluminescence spectroscopy of boron nitride films grown on Si(100) substrates by ion-source-assisted magnetron sputtering of a hexagonal BN target. Three main peaks are observed in the near-band-gap region for hexagonal boron nitride films at energies of 4.90,5.31, and 5.50 eV We also report deep-level emission spectra of predominantly cubic boron nitride films whic...

In this article, we examine the elastic properties of boron-nitride nanotubes, which are embedded in amorphous silicon-boron-nitride ceramics. We employ molecular dynamics simulations using the Parrinello-Rahman approach. To this end, all systems are modeled with a reactive many-body bond order potential due to Tersoff, which is able to describe covalent bonding accurately. We apply external st...

Water-filled nanometer-scale porous structures have gained considerable attention over the past decade due to their enormous promise in substantially improving the performance and efficiency of many applications such as biological/chemical systems,1-3 water purification systems,4 fuel cell devices,5 etc. Single-walled carbon nanotubes (SWCNTs), due to their extraordinary physical and chemical p...

Liquids condensing on solids can form a pattern known as ‘‘breath figures.’’ Here we report similar patterns for liquid boron oxide droplets formed by high temperature oxidation reaction of boron nitride. Boron oxide does not wet boron nitride, so the liquid B2O3 oxide forms small droplets. As oxidation proceeds at 12001C, the oxide created by reaction on the surface migrates to existing drople...

Using the minima hopping global geometry optimization method on the density functional potential energy surface we show that the energy landscape of boron clusters is glasslike. Larger boron clusters have many structures which are lower in energy than the cages. This is in contrast to carbon and boron nitride systems which can be clearly identified as structure seekers. The differences in the p...

A comparison between experimental and theoretical electron Energy Loss Near Edge Structure (ELNES) of B and N K-edges in cubic boron nitride is presented. The electron energy loss spectra of cubic boron nitride particles were measured using a scanning transmission electron microscope. The theoretical calculation of the ELNES was performed within the framework of density functional theory includ...

Sintering of cubic boron nitride (cBN) was carried out by subjecting fine powders of cBN to high pressures and temperatures (P = 50-60 kb, T = 1200-1500°C ) in the presence of boron carbide as the main binding material together with a small amount of aluminium nitride. The composites were characterized by X-ray diffraction, scanning electron microscopy, FTIR, Raman Spectroscopy and microhardnes...

Radiation shielding is an obstacle in long duration space exploration. Boron Nitride Nanotubes (BNNTs) have attracted attention as an additive to radiation shielding material due to B’s large neutron capture cross section. The B has an effective neutron capture cross section suitable for low energy neutrons ranging from 10 to 10 eV and hydrogen is effective at slowing down high energy neutrons....