02118nas a2200253   4500008004100000022001400041245010600055210006900161260007900230300001000309490000700319520118900326653003001515653003701545653001701582653000801599100002001607700002201627700001901649700002201668700002001690700002301710856013101733       2005                        eng d  a1044-580300aSimple oxalate precursor route for the preparation of barium-strontium titanate: Ba1-xSrxTiO3 powders0 aSimple oxalate precursor route for the preparation of bariumstro  a360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USAbELSEVIER SCIENCE INCcJAN  a63-740 v543 a<p>A simple one-step cation-exchange reaction between the stoichiometric solutions of ammonium titanyl oxalate (ATO) and barium hydroxide+strontium nitrate at room temperature (RT) is investigated successfully for the quantitative precipitation of barium-strontium titanyl oxalate (BSTO): Ba1-xSrxTiO(C2O4)(2).4H(2)O (x=0.25) precursor powders with nearly theoretical yield (greater than or equal to99%). The pyrolysis of BSTO at 730degreesC/4 h in air produced barium-strontium titanate (Ba1-xSrxTiO3; BST) powders. The characterization studies on BSTO and BST powders by using various physico-chemical techniques: micro- and chemical analysis, differential thermal analysis (DTA)/thermo-gavimetric analysis (TGA), XRD, FTIR, X-ray fluorescence (XRF) and scanning electron microscopy (SEM) revealed that the powders formed are cubic, highly pure, stoichiometric and sub-micron-sized with nearly uniform size and shape distribution. The ceramic compacts obtained by sintering the BST pellets at 1300degreesC/4 It showed density similar to95%, dielectric constant epsilon(Tc)similar to9500, tan delta-0.15% and T(C)similar to32 degreesC. (C) 2004 Elsevier Inc. All rights reserved.</p>10abarium-strontium titanate10abarium-strontium titanyl oxalate10apermittivity10aXRF1 aKhollam, Y., B.1 aDeshpande, S., B.1 aPotdar, H., S.1 aBhoraskar, S., V.1 aSainkar, S., R.1 aDate, Sadgopal, K.  uhttps://library.ncl.res.in/content/simple-oxalate-precursor-route-preparation-barium-strontium-titanate-ba1-xsrxtio3-powders-002227nas a2200241   4500008004100000022001400041245005500055210005200110260006900162300001200231490000700243520144600250653003001696653003701726653001801763653002101781653001501802100002001817700001901837700002201856700002001878856008701898       2006                        eng d  a0254-058400aSynthesis of star shaped Ba1-xSrTiO3 (BST) powders0 aSynthesis of star shaped Ba1xSrTiO3 BST powders  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcJUN  a295-3000 v973 a<p>Uniform star shaped strontium substituted barium titanyl oxalate Ba1-xSrxTiO(C2O4)(2) (BSTO)/strontium substituted barium titanate, Ba1-xSrxTiO3 (BST) powders were prepared via a simple chemical co-precipitation route with x = 0.15, 0.20, and 0.25. The process involved an addition of 0.1 M solution of titanium tetrabutoxide (BTM) in isopropanol (IPA) to 0.1 M oxalic acid in IPA containing 0.2 M of H2O to produce titanyl oxalate precipitate which was further reacted with 0.1 M solution of ammonium oxalate to obtain 0.1 M clear homogeneous solution of ammonium titanyl oxalate (ATO) with pH 4.25 containing titanium in the form of soluble anionic oxalate species [TiO(C2O4)(2)(2-)]. Stoichiometric quantities of barium hydroxide and strontium nitrate were dissolved in distilled water and its pH was adjusted nearly equal to that of ATO (similar to 4.15) by drop wise addition of dilute HNO3 solution 1:10 (v/v). The addition of this mixed cation precursor solution to ATO solution resulted in precipitation of strontium substituted barium titanyl oxalate (BSTO) having star shaped morphology. The calcination of BSTO precursors at 730 degrees C for 4 h in air produced cubic BST powders (a(o) similar to 4.001, 3.996 and 3.991 angstrom for x = 0. 15, 0.20, 0.25, respectively) having star shaped morphology. SEM, XRD and IFTIR techniques were used to characterize the BSTO/BST powders. (c) 2005 Elsevier B.V. All rights reserved.</p>10abarium-strontium titanate10abarium-strontium titanyl oxalate10acapping agent10aCo-precipitation10aMorphology1 aKhollam, Y., B.1 aPotdar, H., S.1 aDeshpande, S., B.1 aGaikwad, A., B.  uhttps://library.ncl.res.in/content/synthesis-star-shaped-ba1-xsrtio3-bst-powders-1