02023nas a2200241   4500008004100000022001400041245010300055210006900158260007400227300001200301490000700313520114200320653002001462653002101482653001901503653002601522653002301548100002201571700002001593700002001613700001901633856012901652       2005                        eng d  a1385-344900aCharacterization of barium titanate: BaTiO3 (BT) ceramics prepared from sol-gel derived BT powders0 aCharacterization of barium titanate BaTiO3 BT ceramics prepared   aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcNOV  a103-1080 v153 a<p>Sol-gel synthesis was attempted at room temperature by adding drop wise a clear solution (made by reacting BaCO3 with glacial acetic acid) to an equi-molar solution of titanium tetrabutoxide in isopropanol (IPA) and acetic acid. The gelation occurred within 30 minutes. The as-dried gel was calcined at 750 degrees C/6 h in air to obtain carbon free BaTiO3 powders. The resulting BT powders were further pressed into pellets and sintered at 1280 degrees C/4 h in air to get dense ceramics (density similar to 94%). XRD and SEM techniques were used for phase and microstructure analysis respectively. The room temperature relative permittivity (e) of 1280 increased to 7200 (at Curie temperature of 127 degrees C) at 1 kHz frequency. The dissipation factor (tan delta) similar to 1.6% was observed in these samples. Also, the ferroelectric properties such as spontaneous polarization (Ps similar to 13 mu C/cm(2)), coercive field (E-c similar to 4.0 kV/cm) and dielectric strength (similar to 34 kV/cm) are estimated for these samples. These performance parameters are compared with the available standard data from the literature.</p>10abarium titanate10aferroelectricity10aMicrostructure10arelative permittivity10asol-gel processing1 aDeshpande, S., B.1 aGodbole, P., D.1 aKhollam, Y., B.1 aPotdar, H., S.  uhttps://library.ncl.res.in/content/characterization-barium-titanate-batio3-bt-ceramics-prepared-sol-gel-derived-bt-powders-002169nas a2200253   4500008004100000022001400041245008600055210006900141260006900210300001200279490000700291520130700298653001901605653002101624653002301645653001201668100002201680700001901702700002001721700001801741700001701759700002201776856011701798       2006                        eng d  a0254-058400aRoom temperature synthesis of mesoporous aggregates of anatase TiO2 nanoparticles0 aRoom temperature synthesis of mesoporous aggregates of anatase T  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcJUN  a207-2120 v973 a<p>The controlled hydrolysis reaction of titanium tetrabutoxide in presence of acetic acid in isopropanol, i.e. in non-aqueous media was adopted in the present work for the synthesis of nanocrystalline titania followed by aging at ambient conditions for longer duration. The powder XRD shows that the as-dried precursor (without any aging) is non-crystalline in nature. However, room temperature aging for longer duration &gt; 120 days not only helped to develop crystallinity in TiO2 nanoparticles but also led to the formation of their self-assembly towards mesoporous aggregates creating sponge like TiO2 nano-structure having high surface area similar to 250m (2) g(-1)and narrow pore size distribution of 4-5 nm. TEM observations revealed the generation of spherical TiO2 nanoparticles (4-5 nm) assembled to form stable spongy scaffold having porous network structure with pore size 5-6 nm. Also, presence of a pronounced hysteresis loop in BET isotherm is indicative of a 3D-intersection network of the pores of size 4-5 nm. Further heat-treatment to the aged precursor at 400 degrees C/2 h in air modify pore network structure due to sintering of TiO2 particles as is observed in TEM studies and lowering thereby the surface area to 125 m(2) g(-1) (c) 2005 Elsevier B.V. All rights reserved.</p>10aMicrostructure10aporous materials10asol-gel processing10atitania1 aDeshpande, S., B.1 aPotdar, H., S.1 aKhollam, Y., B.1 aPatil, K., R.1 aPasricha, R.1 aJacob, Nalini, E.  uhttps://library.ncl.res.in/content/room-temperature-synthesis-mesoporous-aggregates-anatase-tio2-nanoparticles-0