Self-assembly of very-low height/width aspect-ratio Li3Ni2NbO6 disks embedded in Li3NbO4 epitaxial films

Publication date: Available online 7 December 2016
Source:Thin Solid Films
Author(s): Hideyuki Kawasoko, Ryota Shimizu, Yoshitaka Takagi, Kuniko Yamamoto, Issei Sugiyama, Susumu Shiraki, Taro Hitosugi
We here report the self-assembly of Li3Ni2NbO6 (LNNO) epitaxial disks with very low height/width aspect ratios. An epitaxial LNNO thin film is obtained at a substrate temperature (T s) of 400°C, using a pulsed laser deposition technique, and by increasing the T s to 600°C, Li3NbO4 epitaxial domains are formed inside the LNNO epitaxial film. Further increasing the T s to 700°C leads to the formation of LNNO disks (with diameters of a few micrometers and a typical height of ~100nm) embedded in a Li3NbO4 film. Interestingly, transmission electron microscopy observations reveal that the LNNO disks are separated from the Li3NbO4 films by amorphous compounds, indicating the formation of a planar core-shell structure. Understanding of the growth processes of these unique nanostructures pave the way to fabrication of higher hierarchical structures embedded in thin film matrices.