Self-organized growth of complex oxide Ce : BaTiO3 nano-islands on (1 0 0)MgO by pulsed laser ablation

Pulsed laser ablation epitaxial Stransky-Krastanow growth of self-organized complex oxide Ce:BaTiO3 islands on MgO(1 0 0) substrates is demonstrated. The lattice mismatch of Ce: BaTiO3/MgO heterostructure leads to a strain-dr iven distribution of nanoscale Ce : BaTiO3 islands on the top of a two-dime nsionally grown wetting layer. Atomic force microscopy, X-ray diffraction a nd X-ray energy dispersive spectrometer are used to determine the structure of the wetting layer and morphological dimensions and the composition of t he islands. The square base pyramidal complex oxide islands are observed. T he density of the islands, their average dimension, height, and aspect rati o turn out to be about 140 mu m(-2), 87.9 nm, 9.6 nm, and 0.15, respectivel y, for our experimental condition. Furthermore, the difference of the criti cal thickness between the complex oxide and semiconductor with similar latt ice mismatch and their mechanism are discussed. (C) 1999 Elsevier Science B .V. All rights reserved.