We report direct transmission electron microscopy evidence of self-organized, ordered array of coherent orthogonal column nanostructures in epitaxial La0.8Sr0.2MnO3
(LSMO) thin films grown on (001) LaAlO3
(LAO) using pulsed-laser ablation. The orthogonal column nanostructures have an orthorhombic structure and are epitaxially grown on a continuous cubic perovskite LSMO thin-film layer that is epitaxially grown on (001) LAO substrate. The orthogonal column nanostructures exhibit a narrow size distribution, with the short edges having a length of about 25 nm and the long edge (growth direction) of ∼ 70 nm.
The short edges are parallel to the  and  directions of LAO. All columns are encapsulated by uniformly thick amorphous-like grain boundaries and are “quasi” periodically arranged along the  and  directions of LAO. The continuous epitaxial layer of cubic perovskite structure grows along the  direction with an in-plane orientation relationship with respect to the substrate of 〈100〉LSMOC∥〈100〉LAO,
while the orthorhombic column structures grow along its 
direction with an in-plane orientation relationship of LSMOO∥LAO
The spontaneous formation of such self-organized, coherent column nanostructures can be considered to follow a type of Stranski–Krastanov growth mode without Oswald ripening. © 2002 American Institute of Physics.