Large yield of β-Ga2O3 nanorods with metal Ga tip were efficiently synthesized. They were deposited on surface of amorphous C fibers by decomposition of Ga2O vapor at around 1000℃, where Ga2O vapor was produced at 1360℃ by a reaction between pure Ga2O3 and active carbon powders. The nanorods had diameters ranging from 10 to 100 nm and lengths of up to several tens micrometers. Twins and edge dislocations having a Burgers vector of 0.0859 Å @2.66, 3.66, 1] existed in the nanorods. A redshift of 4-23 cm-1 was found in the Raman scattering spectrum of nanorods compared with that of a pure Ga2O3 powder. This phenomenon was explained qualitatively in terms of the defects in the nanorods.

SiC nanorods with 20-100 nm diameter and 10–100μm length were synthesized by reaction between SiO and amorphous activated carbon (AAC) at 1380℃. Microstructural characterization of the SiC nanorods was carried out by high resolution transmission electron microscopy (HRTEM) and energy dispersive spectroscopy (EDS). The SiC nanorods grow on either a chain or from facets of SiC nanoparticles. They are usually straight and preferentially orientated along the [111] direction. Branching phenomenon exists for these nanorods. Typical SiC nanorod tip was analyzed by HRTEM image and EDS analysis. Based on an experimental analysis, a formation mechanism is proposed to explain the microstructural characterization of the SiC nanorods.

Si3N4/SiC interface structure in SiC-nanocrystal-embedded a-Si3N4 nanorods was studied by high-resolution transmission electron microscopy. The SiC-nanocrystal-embedded a-Si3N4 nanorods were synthesized by the method of carbothermal reduction of SiO in pure N2 atmosphere, while the SiC nanocrystals were produced from a substitution of SiC for Si3N4. Between SiC and Si3N4, there are three kinds of plane configurations and a set of orientation relationships, i.e., Si3N4, and nearly (111)SiC//(1010)Si3N4 with low-angle discrepancy of either 3

α-Si3N4 K15nanorods with 20-80 nm width were synthesized by carbothermal reduction of SiO with amorphous activated carbon (AAC) as a reductant. Microstructural characterization of the synthesized nanorods was carried out by high resolution transmission electron microscopy (HRTEM)and energy dispersive X-ray analysis. Many Si3N4 nanorods were found to be twisted. Each twisted nanorod contained several straight Si3N4 parts. The straight parts had the rod axes orientated along the〈1010〉direction, which is the closest packing direction of a-Si3N4. There were two kinds of joints between the two adjacent straight Si3N4 parts. Formation mechanism of the Si3N4 nanorods is discussed.

Ge3N4 nanobelts 30-300 nm in width were synthesized by thermal reduction of a mixed Ge+SiO2 powder in NH3 atmosphere. These nanobelts were studied by high-resolution transmission electron microscope equipped with an x-ray energy dispersive spectrometer. In these synthesized nanobelts, the existence of α and β phases of Ge3N4 was identified. The a phase exhibiting slight difference from an ideal α-Ge3N4 phase was also found in the present Ge3N4 material. The mechanism of formation of the Ge3N4 nanobelts is discussed.