Accession Number : ADA322548

Title :   Synthesis of Ceramics from Solutions: Functionally Graded Composites, NanoComposites and Single Crystal Thin Films. Epitaxial Growth and Structure of Cubic and Pseudocubic Perovskite Films on Perovskite Substrates.

Descriptive Note : Technical rept. no. 4, Dec 95-Nov 96,

Corporate Author : CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS

Personal Author(s) : Lange, Fred F. ; Langjahr, P. A. ; Wagner, T. ; Ruehle, M.

PDF Url : ADA322548

Report Date : 28 FEB 1997

Pagination or Media Count : 8

Abstract : Cubic and pseudocubic perovskite films on perovskite substrates are used to study the influence of the lattice mismatch on the epitaxial growth of thin films on substrates of the same structure. For the growth of the films, a metalorganic deposition route (MOD) using 2-ethylhexanoates and neodecanoates as precursors, was developed. The decomposition of the precursors was investigated with thermogravimetric analysis (TGA) and x-ray diffraction (XRD). The films were spin-coated on (001)-oriented SrTiO3- and LaAlO3-substrates, pyrolyzed and afterwards annealed between 600 deg C and 1200 deg C. XRD-investigations and conventional transmission electron microscopy (CTEM) show, that epitaxial films with the orientation relationship 100(001) film (parallel lines) 100(001) substrate can be grown. With XRD, it could be shown, that not only ternary oxide films (SrZrO3, BaZrO3 and BaCeO3), but also perovskite solid soulution films (SrTi(0.5)Zr(0.5)O3 and BaCe(0.5)Zr(0.5)O3) can be prepared. Strong interdiffusion, detected by a shift of the film lattice parameter towards the substrate lattice parameter was found in SrZrO3- and BaZrO3-films on SrTiO3, annealed at temperatures above 1050 deg C. High resolution electron microscopy (HREM) studies of SrZrO3 on SrTiO3 show that a crystalline semicoherent interface with a periodical array of misfit dislocations is present.

Descriptors :   *COMPOSITE MATERIALS, *THIN FILMS, *EPITAXIAL GROWTH, *CERAMIC MATERIALS, *PEROVSKITES, TEMPERATURE, ANNEALING, CRYSTAL STRUCTURE, SYNTHESIS, PRECURSORS, X RAY DIFFRACTION, SINGLE CRYSTALS, ORGANOMETALLIC COMPOUNDS, SUBSTRATES, SOLIDS, HIGH RESOLUTION, ELECTRON MICROSCOPY, DISLOCATIONS, OXIDES, ALUMINUM OXIDES, ZIRCONIUM, MOLECULAR STRUCTURE, TITANIUM, TERNARY COMPOUNDS, DECOMPOSITION, BARIUM, STRONTIUM, TITANATES, LANTHANUM, ALUMINATES, THERMOGRAVIMETRIC ANALYSIS.

Subject Categories : Geology, Geochemistry and Mineralogy
      Inorganic Chemistry
      Ceramics, Refractories and Glass
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE