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Title: Polarization switching characteristics of 0.5BaTi{sub 0.8}Zr{sub 0.2}O{sub 3}-0.5Ba{sub 0.7}Ca{sub 0.3}TiO{sub 3} lead free ferroelectric thin films by pulsed laser deposition

We report on the ferroelectricity for morphotropic-phase-boundary lead (Pb) free 0.5BaTi{sub 0.8}Zr{sub 0.2}O{sub 3}-0.5Ba{sub 0.7}Ca{sub 0.3}TiO{sub 3} (0.5BZT-0.5BCT) thin films. Thin films were grown on Pt/Ti/SiO{sub 2}/Si substrate using pulsed laser deposition. Raman spectroscopic data combined with the X-ray diffraction analyses confirm body centered tetragonal crystallographic structure 0.5BZT-0.5 BCT thin films on Pt/Ti/SiO{sub 2}/Si. Polarization studies demonstrate that these 0.5BZT-0.5BCT films exhibit a large remnant and saturation polarization of 37 μC/cm{sup 2} and 40 μC/cm{sup 2}, respectively, with a coercive field of 140 kV/cm. A correlation between polarization dynamics, structural distortion, and phonon vibration is established. The splitting of X-ray diffraction peak of the thin film in the 2θ range of 44.5° to 46.5° represents high degree of tetragonality. The tetragonality factor calculated by Rietveld analysis was found to be 0.006 and can be a major cause for the increased remnant polarization value. It is established from Raman spectra that the non-centrosymmetricity due to the displacement of Ti/Zr ions from its octahedral position is related to the peak position as well as the broadening of the A{sub 1} (LO) optical phonon mode. This increase of broadness in the thin film causes an increase in the dipole moment of the unit cell and, hence,more » the net increase in polarization values.« less
Authors:
 [1] ;  [2] ;  [3] ; ;  [1] ;  [4] ;  [5]
  1. Department of Physics, Astronomy and Materials Science, Missouri State University, Springfield, Missouri 65897 (United States)
  2. (India)
  3. (United States)
  4. National Chemical Laboratory (CSIR-NCL), Council of Scientific and Industrial Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra (India)
  5. Department of Mechanical Engineering, University of Texas at El Paso, El Paso, Texas 79968 (United States)
Publication Date:
OSTI Identifier:
22273569
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 15; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BARIUM COMPOUNDS; CALCIUM COMPOUNDS; CORRELATIONS; DIPOLE MOMENTS; ENERGY BEAM DEPOSITION; FERROELECTRIC MATERIALS; LASER RADIATION; PHONONS; POLARIZATION; PULSED IRRADIATION; RAMAN SPECTRA; SILICON OXIDES; SUBSTRATES; TETRAGONAL LATTICES; THIN FILMS; TITANATES; X-RAY DIFFRACTION; ZIRCONIUM COMPOUNDS; ZIRCONIUM IONS