{"id":64490,"key":"Preparation_of_meta-stable_phases_of_barium_titanate_by_sol-hydrothermal_method","title":"Preparation of meta-stable phases of barium titanate by sol-hydrothermal method","latest":{"id":1224322,"timestamp":"2026-01-09T00:34:33Z"},"content_model":"wikitext","license":{"url":"https://www.appropedia.org/Appropedia:Copyrights","title":"CC-BY-SA-4.0"},"source":"[[Image:BaTiO3.jpg|thumb]]\n\n{{MOST}}\n\n{{Publication data\n| type = Paper\n| cite-as = Selvaraj, M., Venkatachalapathy, V., Mayandi, J., Karazhanov, S. and Pearce, J. M., Preparation of meta-stable phases of barium titanate by sol-hydrothermal method. ''AIP Advances'', '''5''', 117119 (2015), DOI:http://dx.doi.org/10.1063/1.4935645 [https://www.academia.edu/18077811/Preparation_of_meta-stable_phases_of_barium_titanate_by_sol-hydrothermal_method open access]\n}}\n\nTwo low-cost chemical methods of sol–gel and the hydrothermal process have been strategically combined to fabricate barium titanate (BaTiO<sub>3</sub>) nanopowders. This method was tested for various synthesis temperatures (100 <sup>°</sup>C to 250 <sup>°</sup>C) employing barium dichloride (BaCl<sub>2</sub>) and titanium tetrachloride (TiCl<sub>4</sub>) as precursors and sodium hydroxide (NaOH) as mineralizer for synthesis of BaTiO<sub>3</sub> nanopowders. The as-prepared BaTiO<sub>3</sub> 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</sub> 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 <sup>°</sup>C to 250 <sup>°</sup>C, the particles agglomerate. Selective area electron diffraction (SAED) shows that the particles 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</sub> nanopowders can be stabilized by the sol-hydrothermal method.\n\n{{Pearce publications notice}}\n\n== See also ==\n\n* BaTiO<sub>3</sub> has promise as an ultracapacitor for use in electrical storage applications for solar [[photovoltaic]] technology\n* [[Photovoltaic charging of ultracapacitors literature review]] - complete lit review\n* [[Photovoltaic charging of ultracapacitors]] - project page\n* [[Ultracapacitors: MOST]] - methods page, include spec sheets, safety, etc. for using ours.\n* [[Enriched second-harmonic generation in meta-phase barium titanate nanostructures synthesized by sol-gel hydrothermal method]]\n\n{{Page data\n| license = CC-BY-SA-3.0\n| title-tag = Preparation of Meta-Stable Phases of Barium Titanate\n| description = Better crystal structures support new materials. Appropedia describes a sol-hydrothermal method for producing barium titanate with improved stability.\n}}\n\n[[Category:MOST completed projects and publications]]\n[[Category:Materials processing]]"}