Growth and optical properties of FePt:BaTiO₃ nanocomposite films

FePt:BaTiO₃ nanocomposite films consisting of a regular stacking of pure BaTiO₃ (BTO) layers and BTO layers embedding FePt nanocrystals  were grown on (001) MgO substrates by pulsed laser deposition. Transmission electron microscopy experiments on cross-sectional specimens demonstrated the high quality of the epitaxial growth of the different layers, whatever their composition. The structural analysis also gave evidence of a misfit strain relaxation at the BTO/MgO interface. We report and discuss the optical and pholuminescence properties of the nanocomposite films in comparison with the ones recorded in pure BTO films. Our results emphasize the role of nanostructuration and growth processes on the evolution of the observed properties. (paper)