General remarks on the structure and the lattice vibrations o f the different structure groups o f boron and icosahedral boron-rich borides are made. In detail, the lattice vibrations o f the alpha-rhombohedral boron structure group are systematically investigated by group theory. Reflectivity spectra o f boroncarbide o f different chemical com position and preparation and o f B60 were measured...

The B(a; n)N reaction is studied as an activation process in a variety of solid boron-containing neutron shielding materials. The source of a-particles is the neutron capture reaction B(n; a)Li. Samples of boron carbide, boron oxide, and boron nitride are irradiated with thermal neutrons and the rate of N production is determined. N promptly decays, emitting a positron. This positron efficientl...

Boron carbide nanoparticles were made via a reaction of boron, obtained from thermal decomposition of magnesium diboride, with multiwall carbon nanotubes at 1150 ◦C for 3 h in vacuum. The size of the nanoparticles is smaller than 100 nm. The bamboo structure of the multiwall carbon nanotubes is the key to the successful synthesis of such nanoparticles. Good crystallinity was demonstrated by sca...

The discoveries of superconductivity in heavily boron-doped diamond in 2004 and silicon in 2006 have renewed the interest in the superconducting state of semiconductors. Charge-carrier doping of wide-gap semiconductors leads to a metallic phase from which upon further doping superconductivity can emerge. Recently, we discovered superconductivity in a closely related system: heavily boron-doped ...

Green-light-emitting pyrotechnic compositions based on tris(2,2,2-trinitroethyl)borate (TNEB) and boron carbide have been investigated. The best performing formulations were found to be insensitive to various ignition stimuli, and exhibited very high spectral purities and luminosities compared to previously reported green-light-emitting formulations.

The physical properties of nanostructures strongly depend on their structures, and planar defects in particular could significantly affect the behavior of the nanowires. In this work, planar defects (twins or stacking faults) in boron carbide nanowires are extensively studied by transmission electron microscopy (TEM). Results show that these defects can easily be invisible, i.e., no presence of...

Ultra-high temperature ceramics are desirable for applications in the hypersonic vehicle, rockets, re-entry spacecraft and defence sectors, but few materials can currently satisfy the associated high temperature ablation requirements. Here we design and fabricate a carbide (Zr0.8Ti0.2C0.74B0.26) coating by reactive melt infiltration and pack cementation onto a C/C composite. It displays superio...