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ZnSe nanoparticles were synthesized via a simple, effective thermal evaporation method by a vapor phase reaction of Zn and Se powder. Particle characterization was performed by X-ray diffraction (XRD), transmission electron microscopy (TEM). It is found that the higher the growth temperature, the larger the nanoparticles. Obvious blue shift was observed in the photoluminescence (PL) spectra at room temperature with decreasing particle size. Raman spectra of the as-grown ZnSe nanoparticles were compared with that of the bulk ZnSe crystal. Though no obvious peak shift was observed for both the transverse optical (TO) and longitudinal optical (LO) phonon modes within the apparatus spectral resolution, non-symmetrical broadening of the LO phonon mode is obvious, indicating that the phonon lifetime is shorter in ZnSe nanoparticles than in bulk material.

A simple vapor phase growth method was used for large-scale synthesis of high-purity Mn 3 O 4 nanowires on silicon substrates. The microstructure, morphology and chemical composition of as-grown Mn 3 O 4 nanowires were investigated using the X-ray diffraction and electron microscopy methods. The products were composed of pure and single crystalline tetragonal structure Mn 3 O 4 nanowires. The nanowires had an average diameter of ∼200 nm and length of 10 μm. Magnetic measurements showed that Mn 3 O 4 nanowires had a high Curie temperature, T c , around 51 K and a large coercive force of about 5710 Oe.

Aligned TiO2 nanowire arrays were fabricated onto Si wafers by a simple thermal deposition (PVD) method. Scanning electron microscopy and high-resolution transmission electron microscopy observations confirm that the as-prepared TiO2 nanowires are single-crystalline and of high purity. Field emission measurements showed that the TiO2 nanowire arrays could provide stable, high-current electron emission at a low voltage. The emission current monitored over a period of 24 h fluctuated gently but did not show degradation. The cathode-luminescence (CL) images captured by a CCD camera were very bright and their CL intensity was homogeneous. This remarkable performance reveals that TiO2 nanowire arrays are well suited for commercial use in electron devices, particularly flat panel displays.

Selenium dioxide nanowires were fabricated as the co-products of ZnSe nanostructures. The SeO2 nanowires have diameters between 20∼70 nm and lengths up to several hundred micrometers. The morphology and microstructure of the nanowires were analyzed using TEM, and the growth mechanism of the SeO2 nanowires was explained under the framework of a vapor-solid model, in which structure defects may play a very important role in the nanowire growth. The nanostructured SeO2 materials may find application in both catalytic and biological fields.

Silica sheathed titania nanocable arrays were synthesized on Si substrates by using a vapor phase method. The morphology, microstructure, and chemical composition of the nanocables were characterized by using scanning electron microscopy, transmission electron microscopy, and spatial-resolution energy-dispersive X-ray spectroscopy, respectively. Raman spectroscopy combined with the other characterization methods elucidates that the nanocable core is of rutile titania. X-ray photoelectron spectroscopy indicates the existence of Ti−O−Si bonds as well as Ti−O−Ti and Si−O−Si bonds. A possible growth mechanism of the nanocables was also proposed on the basis of thermodynamic and kinetic considerations. The as-grown nanocable arrays may find applications as photocatalysts.

Nanosized manganese oxide particles have been synthesized via vapor phase growth. The diameter of the nanoparticles can be controlled by the growth temperature: the higher the temperature, the larger the diameter of the particle. Magnetization measurements show that the manganese oxide nanoparticles have an obvious ferromagnetic behavior with the Curie temperature around 40 K. The latter is size-dependent, namely: the smaller is the diameter of the particles, the lower is the Curie temperature.

We describe a vapor-phase route to the controllable synthesis of indium oxide micro-and nanopyramids on the silicon wafer via selective epitaxial vapor-solid growth by a methane-assist thermal reduction method. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy revealed that the pyramids were cubic single crystals with a tetragonal symmetry. The size, morphology, and density of pyramids could easily be controlled by tuning reaction parameters. The method has good compatibility with other procedures involved in the microfabrication processes. Laterally grown indium oxide nanorods on the silicon wafer were also prepared via a vapor-liquid-solid mechanism. Those crystalline In2O3 nanorods were about 100 nm in diameter and 1 μm in length. The as-synthesized indium oxide nanopyramids and nanorods could offer novel opportunities for both fundamental research and technological applications.

High-purity ZnO nanowires, which possess branching structures, were prepared by evaporating metal zinc onto thermally oxidized Si wafer. The morphology and microstructure analyses of ZnO crystals were performed by scanning electron microscopy and high-resolution transmission electron microscopy. The nanowires possess hexagonal wurzite structure. The 1-D growth mechanism of ZnO nanowires corresponds to Sears theory. Multiply twinned ZnO fine particles deposited on silica surfaces serve as the growth centers of branching structure. The dendrite ZnO nanowires have potential for building optoelectronic nanodevices with special configurations or as building blocks in the construction of functionalized interfaces.