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The synthesis of novel coaxial C-AlN-C composite nanotubes produced through a chemical substitution reaction in a controllable two-stage process using multiwalled carbon nanotubes (MWCNT) as templates was presented. It was found that the synthesized C-AlN-C composite nanotubes appeared to be slightly faceted. Analysis of the nanotube using EDS revealed the presence of ASl and N within the nanotube with an approximate atomic ratio of 1.00:.97. It was observed that the synthesized nanotubes grown along the [001] direction of the hexagonal AlN, and the (100) plane of AlN is parallel to the (002) plane of graphitic carbon.

The hierarchical AlN comb-like nanostructures self-assembled through a chemical-vapor transport and condensation (CVTC) process were investigated. Field emission (FE) measurements showed that low-threshold FE can be obtained from the synthesized AlN hierarchical nanostructures. Energy dispersive x-ray (EDX) spectroscopy analysis indicated that the synthesized nanostructures were composed of pure Al and N in a molar ratio of 1:0.99. The results show that the intrinsically small value of electron affinity of AlN and the emission from the sharp nanotips and thin edges of the AlN nanoarchitectures contribute to the high emission current.

The synthesis of coaxial cubic aluminum nitride-boron nitride (c-AlN-BN) composite nanotubes was investigated. The synthesis was carried out in a template-free catalyst-free two-stage route. The c-AlN nanotubes were first grown using AlCl3 as a precursor in a NH3/N2 flow. Then the BN coating was grown from B-N-O precursors on the surface of the c-AlN nanotubes. The transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and electron diffraction (ED) study were performed on the nanotubes. The nanotubes were found to be single crystalline in structure.

The domain switching at the nanoscale is studied at both −Z and +Z surfaces of a lithium niobate crystal. A remarkable difference between both surfaces is experimentally observed by scanning probe microscopy, and is theoretically analyzed by the structural property and the chemical bonding structure of the lithium niobate crystal. The domain switching at the −Z surface is much easier and more stable than that at the +Z surface, which makes lithium niobate crystals have potential applications in the future domain engineering, especially at the nanoscale level.

Single-crystal ZnSe nanowires have been synthesized via a thermochemical method in a N 2 atmosphere with CO and H 2 gases. The as-prepared ZnSe nanowires have a mean diameter of 40 nm and a length of 1 μm. The nanowires are single crystals with a hexagonal structure growing along the [0 0 1] direction. A self-catalyzed vapor–liquid–solid process is proposed for the formation of such nanowires. The as-prepared nanowires show two emission bands at ca. 447 and 617 nm.

Zn nanosheets have been synthesized by a simple thermochemical reaction process at a N 2 atmosphere with CO and H 2 gases which were produced in situ. The synthesized Zn nanosheets have dimensions of tens of microns and an average thickness of about 20 nm. These nanosheets were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and a high-resolution transmission electron microscope (HRTEM) equipped with an X-ray energy dispersive spectrometer. The nanosheets are single crystals with a hexagonal structure, which grow along both [1 0 0] and [0 1 0] directions within the (0 0 1) planes.

Two kinds of wlilegap-sencieotcductor nanowires, Tb-doped AlN nanowire arrays on Si and freestanding BN nanowires, were fabricated by different catalyst-free methods. Well-aligned Tb-doped AlN nanowire arrays were grown on the Si (111) substrate by magnetron sputtering method. Free-standing BN nanowires were grown by heat-treatment of B-N-O precursor and graphite powders. The crystal structure of nanowires was characterized by using X-ray diffraction and transmission electron microscopy. Cathodo-luminescence (CL) observation was performed with a field emission scanning electron microscope operating with an electron beam lower than 5 kV. CL spectra mapping as well as monochromatic CL imaging clearly revealed not only the variation of the luminescence spectra, of different nanowires but also that along the single wire. Our results demonstrates the advantage of CL for the characterization of nanowires.

Boron nitride whiskers with a special structure have been synthesized by a thermal reaction process. The as-prepared BN whiskers have a length of tens of micrometers and a mean diameter of 500 nm. High-resolution TEM analysis shows that the as-prepared BN whiskers can be described as a nanofiber-interweaved network. Infrared and electron energy loss spectra reveal that the BN whiskers are composed of both sigma-sp2 and sigma-sp3 chemical bonds. The UV-vis absorption spectrum displays the energy band gap of the BN whiskers and multiple fine absorption peaks of the phonon-electron coupling. Both photoluminescence (PL) and cathodoluminescence (CL) measurements show the specially structured BN emits strong UV and visible luminescences, which is a promising material for deep-blue and UV applications.

Hollow boron nitride (BN) nanocages (nanospheres, image on the left) and BN-nanocage-encapsulated GaN nanocrystals (right) have been synthesized by using a homemade B-N-O precursors. The as-prepared BN hollow nanocages have typically spherical morphologies with diameters ranging from 30 to 200 nm. The nanocages have crystalline structures. Peanutlike nanocages with double walls have also been observed; their internal space is divided into seperated compartments by the internal walls. The method is extended to sheathe nanocrystals with BN nanocages; BN-shell/GaN-core nanostructures have been successfully fabriacted. The method may be generally applicable to the fabrication BN-sheathed nanocrystals.