Thin film deposition of double perovskite oxides for multilayer device applications

Publication date: 31 January 2017
Source:Thin Solid Films, Volume 622
Author(s): A. H. Johnson, P. Morris, R. Ricciardo, P.M. Woodward
The double perovskite compounds Sr2AlTaO6, Sr2Al0.5Ga0.5TaO6, Sr2GaTaO6, Sr2CrNbO6, and Sr2NiWO6 (a p =3.900, 3.924, 3.944, 3.940, 3.941Å respectively) have been investigated for use as buffer layer materials to aid in high quality thin film growth of the desired half-metallic double perovskite Sr2FeMoO6 (a p =3.947Å). Chosen for their closely matching lattice parameters and insulating properties, the proposed buffer materials have been deposited by pulsed laser deposition and are found to be pure phase and epitaxial. X-ray diffraction, atomic force microscopy, Rutherford backscattering, and transmission electron microscopy have been used to characterize the films' structure, surface roughness, and stoichiometry. Off-stoichiometry and structural defects are shown to allow strain relaxation of the films, thereby maintaining the smooth surfaces required for multilayer deposition.