Simple oxalate precursor route for the preparation of barium-strontium titanate: Ba{sub 1-x}Sr{sub x}TiO{sub 3} powders

Journal Article · Sat Jan 15 04:00:00 EST 2005 · Materials Characterization

DOI:https://doi.org/10.1016/j.matchar.2004.11.002· OSTI ID:20748656

Khollam, Y B ^[1]; Deshpande, S B ^[2]; Potdar, H S ^[2]; Bhoraskar, S V ^[1]; Sainkar, S R ^[2]; Date, S K ^[1]

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1. Department of Physics, University of Pune, Pune-411 007 (India)
2. Physical and Materials Chemistry Division, National Chemical Laboratory, Pune-411 008 (India)

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): Ba{sub 1-x}Sr{sub x}TiO(C{sub 2}O{sub 4}){sub 2}.4H{sub 2}O (x=0.25) precursor powders with nearly theoretical yield ({>=}99%). The pyrolysis of BSTO at 730 deg. C/4 h in air produced barium-strontium titanate (Ba{sub 1-x}Sr{sub x}TiO{sub 3}; 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-gravimetric 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 1300 deg. C/4 h showed density {approx}95%, dielectric constant {epsilon}(Tc){approx}9500, tan {delta}{approx}0.15% and T{sub C}{approx}32 deg. C.

• OSTI ID: 20748656
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: 1 Vol. 54; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM
BARIUM HYDROXIDES
CERAMICS
ION EXCHANGE
OXALATES
PERMITTIVITY
POWDERS
PRECIPITATION
PRECURSOR
PYROLYSIS
SCANNING ELECTRON MICROSCOPY
SINTERING
SOLUTIONS
STOICHIOMETRY
STRONTIUM
STRONTIUM NITRATES
THERMAL GRAVIMETRIC ANALYSIS
TITANATES
X-RAY DIFFRACTION
X-RAY FLUORESCENCE ANALYSIS