Abstract: ZnO nanocables were synthesized on gold coated silicon(100) substrate by zinc powder evaporation at 550 ℃. The source materials were pure zinc and tin powders with mass ratio of 1∶1 and the experiment was carried out under a constant flow of Ar(98%)/O₂(2%) gas mixture(300 sccm(standard cubic centimeters per minute) in a quartz tube. SEM images showed that the nanocables were obtained in large-scale and the diameters and lengths of the nanocables were about 50 nm and several micrometers respectively. XRD, TEM and EDX investigations confirmed the core-shell structure, i.e. the core zone was single crystalline ZnO and the shell zone was SiOx amorphous layer. Interestingly, the ZnO core was grown along a unique direction of [2021], which was quite different from the conventional fast growth direction of〈0001〉,〈0110〉 and 〈2110〉of 1D ZnO nanoscale materials. A possible mechanism was also proposed. Firstly, gold film served as catalyst and the nanocables grew out from the surface of Au-Si-Zn liquid alloys；secondly, tin powders were used as inhibitor to keep a low partial pressure of zinc vapor.

Key words: Nanocables, ZnO, SiO_x, Synthesis, Growth mechanism