Cross-medal arrays of Ta-doped rutile titania.

A rutile microstructure with a novel cross-medal morphology was prepared via a hydrothermal method by using a Tantalum foil as both the doping source and the substrate. This rutile cross-medal prefers to grow along an unprecedented preferential orientation of <110> directions from the substrate, which is very different from the traditional c-axis. The new material exhibits highly enhanced field emission (FE) properties.