Combining reflection high-energy electron diffraction, high-resolution transmission electron microscopy, and high-angle annular dark field scanning transmission electron microscopy we unveil the existence of a peculiar transition from a three-dimensional to a two-dimensional growth mode in anatase TiO2/LaAlO3 heterostructures. Such a growth dynamics is accompanied by Al interdiffusion from substrate to the growing film up to a critical thickness of 20 nm. With the extra support of ab initio calculations, we show that the crossover between the two growth modes corresponds to the formation of two distinct regions characterized by (103)- and (101)-oriented crystallographic shear superstructures, occurring in the upmost film region and in proximity of the film/substrate interface, respectively.
|Titolo:||Evolution of nanostructures of anatase TiO2 thin films grown on (001)LaAlO3|
ROSSI, GIORGIO (Penultimo)
|Parole Chiave:||Composition; Defects and impurities; Density functional theory; Gradient and other corrections; High-resolution transmission electron microscopy; Local density approximation; Segregation; Thin-film structure and morphology|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2013|
|Digital Object Identifier (DOI):||10.1007/s11051-013-1735-x|
|Appare nelle tipologie:||01 - Articolo su periodico|