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-003023nas a2200337   4500008004100000022001400041245008600055210006900141260012500210300001100335490000800346520187100354653002202225653002502247653001802272653001802290653002002308653001802328653001702346653001202363653001802375653003102393100002002424700001402444700001902458700001702477700002502494700002702519700001902546856012002565       2010                        eng d  a0021-897900aMagnetic and dielectric properties and Raman spectroscopy of GdCrO3 nanoparticles0 aMagnetic and dielectric properties and Raman spectroscopy of GdC  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJAN  a0139120 v1073 a<p>The rare earth orthochromites are extremely interesting due to the richness of their optical, dielectric, and magnetic properties as well as due to their multiferroic properties which make them suitable materials to study in the nanoregime. However, the wet-chemical synthesis of these materials in nanosize is nontrivial. Here, we report for the first time, the detailed Raman spectra as well as magnetic and dielectric properties of chemically synthesized GdCrO3 nanoparticles of size ranging from 40 to 60 nm. The magnetic properties are dictated by competing Cr3+-Cr3+, Gd3+-Cr3+, and Gd3+-Gd3+ superexchange interactions in different temperature regions, resulting into an antiferromagnetic ordering at 167 K due to the Cr3+-Cr3+ followed by weak ferromagnetic ordering due to the onset of Cr3+-Gd3+ interactions. At lower temperature, it shows weak antiferromagnetic ordering due to Gd3+-Gd3+ interaction. Below 95 K, GdCrO3 nanoparticles showed the presence of negative magnetization due to Gd3+ and Cr3+ interactions resulting into weak ferromagnetic coupling. The Raman spectroscopy shows the characteristic Raman shifts indicating that below 450 cm(-1), Gd3+ ions play a dominant role in determining the phonon frequencies of GdCrO3, and above 450 cm(-1), the Cr+3 ions dominate. We also present for the first time the low temperature dielectric constant and loss tangent data for GdCrO3 in a broad temperature and frequency range. The dielectric constant shows a decrease in comparison to the bulk values due to the size dependent effects. It also shows a peak centered at around 320 K above which it shows a sharp decrease. The dielectric loss value in GdCrO3 nanoparticles is quite small and shows an interesting frequency dependent anomaly at lower temperature which might be due to the coupling between magnetic and dielectric order parameters.</p>10adielectric losses10agadolinium compounds10aMagnetisation10aMultiferroics10ananofabrication10aNanoparticles10apermittivity10aphonons10aRaman spectra10asuperexchange interactions1 aJaiswal, Adhish1 aDas, Raja1 aVivekanand, K.1 aMaity, Tuhin1 aAbraham, Priya, Mary1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/magnetic-and-dielectric-properties-and-raman-spectroscopy-gdcro3-nanoparticles-0