Orientational ordering of solution derived epitaxial Gd-doped ceria nanowires induced by nanoscratching

When one-dimensional nanostructures are epitaxially grown on a substrate a key goal is to control the nanowire's position and orientation. Nanoscratching of single crystalline (001)- LaAlO(3) substrates is demonstrated to be extraordinarily effective in directing the self-assembly of Ce(0.9)Gd(0.1)O(2-y) epitaxial nanowires grown by chemical solution deposition. The local anisotropic elastic strain field imposed by the indentation lines is responsible for the breaking of the pre-existing orientation energy degeneracy and selects the nanowires' orientation parallel to the lines to an extent that can reach 100%.