Accession Number : ADA290101

Title :   Pulsed Laser Deposition of Ferroelectric Thin Films in Conjunction with Superconducting Oxides,

Corporate Author : ARMY RESEARCH LAB WATERTOWN MA MATERIALS DIRECTORATE

Personal Author(s) : Sengupta, S. ; Sengupta, L. C. ; Demaree, J. D. ; Kosik, W.

PDF Url : ADA290101

Report Date : DEC 1994

Pagination or Media Count : 18

Abstract : The possibility of combining ferroelectrics and superconductors has been of interest for use in memory storage devices. Additionally, superconductors offer crystal structures compatible to the epitaxial growth of the ferroelectric, Ba(0.6)Sr(0.4)TiO3 (BSTO), which is cubic at this stoichiometry. BSTO has a lattice constant of 3.94 A as compared to the superconducting Pr(2-x)Ce(x)CuO4 tetragonal single crystal which also has a lattice constant of a=3.94 A. (minor variations with Cerium content). In this study, ferroelectric thin films of BSTO were deposited on single crystals of Pr2CuO4 and Pr(2-x)Ce(x)CuO4. The optical constants of the substrates, single crystals of Pr2CuO4 and Pr(2-x)Ce(x)CuO4, were determined using Variable Angle Spectroscopic Ellipsometry (VASE) and the composition and crystal structure were examined using Rutherford Backscattering Spectrometry (RBS) with ion beam channeling. The substrate/film interfaces and the compositional variation in the films were also studied with RBS and with SEM/EDS. Glancing angle x-ray diffraction was used to verify the epitaxial nature of the films. The effect of the deposition parameters (laser repetition rate, oxygen backfill pressure, and deposition geometry) on the quality of the films was experimented with previously and only the optimized parameters were used. (jg)

Descriptors :   *SUPERCONDUCTORS, *THIN FILMS, *PULSED LASERS, *DEPOSITION, *OXIDES, *FERROELECTRIC MATERIALS, OPTICAL PROPERTIES, OPTIMIZATION, REPETITION RATE, SPECTROSCOPY, INTERFACES, PARAMETERS, X RAY DIFFRACTION, SINGLE CRYSTALS, SPECTROMETRY, EPITAXIAL GROWTH, SUBSTRATES, BACKSCATTERING, LASERS, VARIABLES, VARIATIONS, CHEMICAL COMPOSITION, MEMORY DEVICES, COPPER, CERIUM, GEOMETRY, ELLIPSOMETERS, STORAGE, PRASEODYMIUM, BARIUM, STRONTIUM, STOICHIOMETRY.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Lasers and Masers
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE