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Title: Preparation of meta-stable phases of barium titanate by Sol-hydrothermal method

Two low-cost chemical methods of sol–gel and the hydrothermal process have been strategically combined to fabricate barium titanate (BaTiO{sub 3}) nanopowders. This method was tested for various synthesis temperatures (100 °C to 250 °C) employing barium dichloride (BaCl{sub 2}) and titanium tetrachloride (TiCl{sub 4}) as precursors and sodium hydroxide (NaOH) as mineralizer for synthesis of BaTiO{sub 3} nanopowders. The as-prepared BaTiO{sub 3} powders were investigated for structural characteristics using x-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The overall analysis indicates that the hydrothermal conditions create a gentle environment to promote the formation of crystalline phase directly from amorphous phase at the very low processing temperatures investigated. XRD analysis showed phase transitions from cubic - tetragonal - orthorhombic - rhombohedral with increasing synthesis temperature and calculated grain sizes were 34 – 38 nm (using the Scherrer formula). SEM and TEM analysis verified that the BaTiO{sub 3} nanopowders synthesized by this method were spherical in shape and about 114 - 170 nm in size. The particle distribution in both SEM and TEM shows that as the reaction temperature increases from 100 °C to 250 °C, the particles agglomerate. Selective area electron diffraction (SAED) shows that the particlesmore » are crystalline in nature. The study shows that choosing suitable precursor and optimizing pressure and temperature; different meta-stable (ferroelectric) phases of undoped BaTiO{sub 3} nanopowders can be stabilized by the sol-hydrothermal method.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [5]
  1. Department of Physics, R.D. Govt. Arts College, Tamilnadu, Sivaganga - 630561 (India)
  2. (India)
  3. Department of Physics/Centre for Materials Science and Nanotechnology, University of Oslo, P.O Box 1048 Blindern, NO-0316 Oslo (Norway)
  4. Department of Material Science, School of Chemistry, Madurai Kamaraj University, Tamilnadu Madurai-625 021 (India)
  5. (United States)
  6. Department of Solar Energy, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway)
  7. Department of Materials Science & Engineering, Michigan Technological University (United States)
Publication Date:
OSTI Identifier:
22492178
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 11; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AMORPHOUS STATE; BARIUM CHLORIDES; ELECTRON DIFFRACTION; FERROELECTRIC MATERIALS; GRAIN SIZE; HYDROTHERMAL SYNTHESIS; NANOSTRUCTURES; ORTHORHOMBIC LATTICES; PARTICLES; PHASE TRANSFORMATIONS; POWDERS; SCANNING ELECTRON MICROSCOPY; SODIUM HYDROXIDES; SOL-GEL PROCESS; TITANATES; TITANIUM CHLORIDES; TRANSMISSION ELECTRON MICROSCOPY; TRIGONAL LATTICES; X-RAY DIFFRACTION