(100)-Oriented SrTiO3/BaTiO3 Artificial Superlattices Fabricated by Chemical Solution Deposition

Epitaxially grown SrTiO 3 (100)/BaTiO 3 (100) artificial superlattices with 7-nm-thick layers were synthesized on (100) platinum-coated (100) magnesium oxide substrates by a chemical solution deposition method. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) revealed cube-on-cube epitaxial growth. The Z-contrast HAADF-STEM image indicated that the SrTiO 3 and BaTiO 3 layers were fabricated without the intermixing of A-site atoms. The defects can only be observed in the boundary between the SrTiO 3 and BaTiO 3 layers. There was a mismatch of 3.0% between the in-plane lattice parameters of the SrTiO 3 and BaTiO 3 layers. This lattice mismatch induced the defects between the SrTiO 3 and BaTiO 3 layers. Inducing the defects between the layers relaxed the misfit strain.