In situ X-ray diffraction and the evolution of polarization during the growth of ferroelectric superlattices

• Published in: Nature communications 2015-12, Vol.6 (1), p.10136-10136, Article 10136
• Main Authors: Bein, Benjamin, Hsing, Hsiang-Chun, Callori, Sara J., Sinsheimer, John, Chinta, Priya V., Headrick, Randall L., Dawber, Matthew
• Format: Article
• Language: English
• Subjects: 639/301/119/544; 639/301/119/996; 639/638/11/879; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Ferroelectrics; Humanities and Social Sciences; MATERIALS SCIENCE; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms10136

In epitaxially strained ferroelectric thin films and superlattices, the ferroelectric transition temperature can lie above the growth temperature. Ferroelectric polarization and domains should then evolve during the growth of a sample, and electrostatic boundary conditions may play an important role. In this work, ferroelectric domains, surface termination, average lattice parameter and bilayer thickness are simultaneously monitored using in situ synchrotron X-ray diffraction during the growth of BaTiO 3 /SrTiO 3 superlattices on SrTiO 3 substrates by off-axis radio frequency magnetron sputtering. The technique used allows for scan times substantially faster than the growth of a single layer of material. Effects of electric boundary conditions are investigated by growing the same superlattice alternatively on SrTiO 3 substrates and 20 nm SrRuO 3 thin films on SrTiO 3 substrates. These experiments provide important insights into the formation and evolution of ferroelectric domains when the sample is ferroelectric during the growth process. X-ray diffraction provides valuable information on the crystalline order of materials, such as the spacing of atomic layers. Here, the authors demonstrate rapid in situ X-ray diffraction measurements of strained ferroelectric oxide thin film superlattices during their layer-by-layer deposition.