Figure 4.

aDigital camera image of a SiC–W18O49double-layer nanostructure sample showing density gradient owing to mass transport of tungsten oxide source material; andbdSEM image from different regions of the sample having only SiC nanowires, low density W18O49and high density W18O49nanorods, respectively

Kim et al. Nanoscale Research Letters 2009 4:802-808   doi:10.1007/s11671-009-9318-6