Characterization of single transition metal oxide nanorods by combining atomic force microscopy and polarized micro-Raman spectroscopy

Accurate chemical and structural characterization of free-standing zinc oxide (ZnO) and hematite (α-Fe2O3) nanorods has been carried out using an AFM/Raman correlative technique under polarized light. ZnO nanorods are found to be wurtzite-type single crystalline objects homogeneous in composition and grown along their principal axis of symmetry. Hematite specimens are rhombohedral corundum-type single crystals grown along a direction orthogonal to their principal axis of symmetry and exhibiting structural disorder. Certain hematite nanorods turn out to be very sensitive to laser heating. These studies reveal the high potential of the coupled AFM/Raman technique to examine the properties of these promising nanomaterials.