Tiny SiO2 nano-wires (SiO2-NWs) were synthesized on a p-Si (1 1 1) wafer by the chemical-vapor-deposition method. The minimum diameter of the nano-wires was around 9 nm, and the length was longer than 10μm. The results of transmission electron microscopy shows that the amorphous nano-wires were composed of Si and O with an approximate atomic ratio of 1:2. Furthermore, the photoluminescence behavior of the SiO2-NWs has been also checked.

A large-scale crystalline silicon nanowires (SiNWs) with a diameter of ∼30 nm andlength of tens of micrometers on Al2O3 templates andsilicon wafers were synthesizedby the thermal evaporation of silicon monoxide (SiO). The SiNWs were measuredby transmission electron microscopy, scanning electron microscopy, X-ray di4raction andRaman spectroscopy, respectively. It was pointedout that the SiNWs possessedthe well crystalline structure. Therefore, it is consideredthat SiO couldbe usedas Si sources to produce larger-scale SiNWs andcrystalline SiNWs may grow from amorphous nuclei.

The thermal stability of oxygen precipitates formed by prolonged annealing at 1000℃ in conventional Czochralski silicon and nitrogen-doped Czochralski silicon has been comparatively investigated. It was found that a majority of the existing oxygen precipitates in the nitrogen-doped silicon were dissolved by both conventional furnace annealing and rapid thermal annealing at 1200℃, while those in the conventional Czochralski silicon dissolved at 1250℃, as a result of nitrogen enhancing denser oxygen precipitates with smaller size. Furthermore, it can be considered that the dissolution of oxygen precipitates is primarily determined by the annealing temperature.

Ordered silicon nanowires (SiNWs) with single crystal structure were synthesized using nanochannel-Al2O3 (NCA) and the chemical vapor deposition (CVD) method. Firstly, the SiNWs with nearly amorphous structure were fabricated at 500℃; then the SiNWs with crystalline structure were obtained by annealing an as-received sample at 800 C. The average diameter and length of the SiNWs are 40-70 nm and 10 mm, respectively. The Raman shift related to the crystallization and the amorphous SiNWs was analyzed.

Aligned single crystal superconducting MgB2 nanowires were synthesized on nano-channel-Al2O3 (NCA) substrates. At first, aligned single crystal boron nanowires were prepared by the chemical vapour deposition process. Then magnesium was incorporated in a sealed vacuum quartz tube to form aligned single crystal superconducting MgB2 nanowires. The diameters of the MgB2 nanowires were in the range of 20-150nm. Finally, there are indications that the nanowires had a superconducting transition temperature (Tc) at ～33 K.