Growth and characterization of well-aligned RuO_2/R-TiO_2 heteronanostructures on sapphire (100) substrates by reactive magnetron sputtering

摘要

We report the growth of well-aligned RuO_2/R-TiO_2 heteronanostructures on sapphire (100) substrates by reactive magnetron sputtering using Ti and Ru metal targets under different conditions. The surface morphology and structural properties of the as-deposited heteronanostructures were characterized using field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and selected-area electron diffractometry (SAED). The FESEM micrographs and XRD patterns indicated the growth of vertically aligned RuO_2(001) nanotubes and twinned V-shaped RuO_2(101) nanowedges (NWs) on top of R-TiO_2 nanorods under different sputtering pressures. TEM and SAED characterizations of the V-shaped RuO_2 NWs showed that the NWs are crystalline RuO_2 with twin planes of (101) and twin direction of [101] at the V-junction.