Structural and electrical properties of c-axis epitaxial homologous Srm−3Bi4TimO3m+3Srm−3Bi4TimO3m+3 (m=3,(m=3, 4, 5, and 6) thin films

Abstract

c-axis epitaxial thin films of Bi-layered homologous Srm−3Bi4TimO3m+3Srm−3Bi4TimO3m+3 (m=3,(m=3, 4, 5, and 6) were fabricated on (001) SrTiO3SrTiO3 single crystal substrates by pulsed laser deposition, respectively. Microstructures of the films were systematically characterized by x-ray diffraction (including θ–2θ scans, rocking curve scans and ϕ scans), atomic force microscopy, and transmission electron microscope. Epitaxial relations were established to be (001)Srm−3Bi4TimO3m+3∥(001)SrTiO3(001)Srm−3Bi4TimO3m+3∥(001)SrTiO3 and [10]Srm−3Bi4TimO3m+3∥[010]SrTiO3[11̄0]Srm−3Bi4TimO3m+3∥[010]SrTiO3 by ϕ scans and selected area diffraction. A special kind of atomic shift along the [001] direction and a slight atomic vibration of TiO6TiO6 octahedra were revealed and discussed. The room-temperature dielectric constants of these epitaxial films measured by using an evanescent microwave probe were 245±23,245±23, 237±13,237±13, 272±19,272±19, and 221±20221±20 for films with m=3,m=3, 4, 5, and 6 respectively. © 2003 American Institute of Physics.