Study on transport pathway in oxide nanowire growth by using spacing-controlled regular array

Metal oxide nanowires formed via vapor-liquid-solid (VLS) process are promising nanoscale building blocks. Although understanding material transport pathways across three phases is crucial to realize well-defined oxide nanowires, such knowledge is unfortunately far from comprehensive. Here we investigate the material transport pathway in VLS grown MgO nanowires by utilizing spacing-controlled regular array. Defining the regular spacing of catalysts allows us to extract the information of transport pathway for each catalyst. We found the significant contribution of vapor phase transport pathway rather than the surface diffusion transport. This result highlights the critical role of re-evaporation process on VLS oxide nanowires. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3660246]