J. Phys. IV France 11 (2001) Pr11-267-Pr11-272
Modeling the diffraction profiles of CVD-grown perovskite oxide superlatticesE. Dooryhee1, J.L. Hodeau1, M. Nemoz1, J.A. Rodriguez1, C. Dubourdieu2, R. Pantou2, M. Rosina2, F. Weiss2, J.P. Sénateur2, M. Audier2, H. Roussel2 and J. Lindner3
1 Laboratoire de Cristallographie, BP, 166X, 38042 Grenoble, France
2 Laboratoire des Matériaux et du Génie Physique, ENSPG, BP. 46, 38402 Saint-Martin-d'Hères, France
3 AIXTRON AG, Kackerstr, 15-17, 52072 Aachen, Germany
(BaTiO3/SrTiO3)15 superlattices are grown by chemical vapor deposition of organic metals (MOCVD) on <001> oriented Nb-doped SrTiO3 substrates. The source uses a pulsed liquid-injection system, with a unique precursor solution for each compound. Using a monochromatic, parallel X-ray synchrotron beam in the θ/2θ reflection diffraction geometry, the (00L) diffraction profiles are recorded from L=l to L=8. The observed satellite peaks around the fundamental (00L) Bragg reflections indicate a highly coherent superlattice arrangement, well epitaxied on the substrate. The diffraction profiles are fitted, taking into account the structural and chemical disorder which depart from the ideal defect-free perovskite superlattice. The statistical fluctuations of the thickness of each sub-layer and the coherence length of the stacking are introduced. With this modelisation, we have quantified the macro-strain and the large interdiffusion which take place at the BaTiO3/SrTiO3 interface.
© EDP Sciences 2001