Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-24T11:31:59.605Z Has data issue: false hasContentIssue false

Synthesis of nanometer-sized particles of barium orthotitanate prepared through a modified reverse micellar route: Structural characterization, phase stability and dielectric properties

Published online by Cambridge University Press:  01 October 2004

Tokeer Ahmad
Affiliation:
Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India
Ashok K. Ganguli*
Affiliation:
Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Nanoparticles of barium orthotitanate (Ba2TiO4) was obtained using microemulsions (avoiding Ba-alkoxide). Powder x-ray diffraction studies of the powder after calcining at 800 °C resulted in a mixture of orthorhombic (70%) and monoclinic (30%) phases. The high-temperature orthorhombic form present at 800 °C was due to the small size of particles obtained by the reverse micellar route. Pure orthorhombic Ba2TiO4 was obtained on further sintering at 1000 °C with lattice parameters a = 6.101(2) Å, b =22.94(1) Å, c = 10.533(2) Å (space group, P21nb). The particle size obtained from x-ray line broadening studies and transmission electron microscopic studies was found to be 40–50 nm for the powder obtained after heating at 800 °C. Sintering at 1000 °C showed increase in grain size up to 150 nm. Our studies corroborate well with the presence of a martensitic transition in Ba2TiO4. The dielectric constant was found to be 40 for Ba2TiO4 (at 100 kHz) for samples sintered at 1000 °C. The dielectric loss obtained was low (0.06) at 100 kHz.

Type
Articles
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Beauger, A., Mutin, J.C. and Niepce, J.C.: Synthesis reaction of barium titanate(IV). Part 1. Effect of the gaseous atmosphere upon the thermal evolution of the system barium carbonate-titanium dioxide. J. Mater. Sci. 18, 3041 (1983).CrossRefGoogle Scholar
2Beauger, A., Mutin, J.C. and Niepce, J.C.: Synthesis reaction of metatitanate BaTiO3. Part 2. Study of solid-solid reaction interfaces. J. Mater. Sci. 18, 3543 (1983).CrossRefGoogle Scholar
3Murray, J.F.: Causes and effects of phases other than tetragonal BaTiO3 in barium titanate. Am. Ceram. Soc. Bull. 37, 476 (1958).Google Scholar
4Beauger, A., Mutin, J.C. and Niepce, J.C.: Role and behaviour of orthotitanate Ba2TiO4 during the processing of BaTiO3 based ferroelectric ceramics. J. Mater. Sci. 19, 195 (1984).CrossRefGoogle Scholar
5Gunter, J.R. and Jameson, G.B.: Orthorhombic barium orthotitanate, α′-Ba2TiO4. Acta Crystallogr. C 40, 207 (1984).CrossRefGoogle Scholar
6Bland, J.A.: The crystal structure of barium orthotitanate. Acta Crystallogr. 14, 875 (1961).CrossRefGoogle Scholar
7Lee, S.J., Biegalski, M.D. and Kriven, W.M.: Powder synthesis of barium titanate and barium orthotitanate via an ethylene glycol complex polymerization route. J. Mater. Res. 14, 3001 (1999).CrossRefGoogle Scholar
8Pfaff, G.: Sol-gel synthesis of barium titanate powders of various compositions. J. Mater. Chem. 2, 591 (1992).CrossRefGoogle Scholar
9Marks, O., Gunter, J.R. and Hofer, F.: Electron microscopy of barium ortho-titanate and the products of its reaction with carbon dioxide. React. Solids 6, 217 (1988).CrossRefGoogle Scholar
10Ritter, J.J., Roth, R.S. and Blendell, J.E.: Alkoxide precursor synthesis and characterization of phases in the barium titanate oxide system. J. Am. Ceram. Soc. 69, 155 (1986).CrossRefGoogle Scholar
11Phule, P.P. and Risbud, S.H.: Low-temperature synthesis and processing of electronic materials in the BaO-TiO2 system. J. Mater. Sci. 25, 1169 (1990).CrossRefGoogle Scholar
12Potdar, H.S., Deshpande, S.B. and Date, S.K.: Alternative route for synthesis of barium titanyl oxalate: Molecular precursor for microcrystalline barium titanate powders. J. Am. Ceram. Soc. 79, 2795 (1996).CrossRefGoogle Scholar
13Sekhar, M.A., Dhanraj, G., Bhat, H.L. and Patil, K.C.: Synthesis of fine-particle titanates by the pyrolysis of oxalate precursors. J. Mater. Sci.-Mater. Electron . 3, 237 (1992).CrossRefGoogle Scholar
14Kandori, K., Kon-No, K. and Kitahara, A.: Formation of ionic water/oil microemulsions and their application in the preparation of calcium carbonate particles. J. Colloid Interface Sci. 122, 78 (1988).CrossRefGoogle Scholar
15Pileni, M.P., Motte, L. and Petit, C.: Synthesis of cadmium sulfide in situ in reverse micelles: Influence of the preparation modes on size, polydispersity, and photochemical reactions. Chem. Mater. 4, 338 (1992).CrossRefGoogle Scholar
16Chhabra, V., Lal, M., Maitra, A.N. and Ayyub, P.: Preparation of ultrafine high density gamma ferric oxide using aerosol OT microemulsions and its characterization. Colloid Polym. Sci. 273, 939 (1995).CrossRefGoogle Scholar
17Beck, C., Haartl, W. and Hempelmann, R.: Size-controlled synthesis of nanocrystalline BaTiO3 by a sol-gel type hydrolysis in microemulsion provided nanoreactors. J. Mater. Res. 13, 3174 (1998).CrossRefGoogle Scholar
18Ahmad, T. and Ganguli, A.K. Nanostructured barium titanate prepared through a modified reverse micellar route: Structural distortion and dielectric properties (unpublished)Google Scholar
19Savitzky, A. and Golay, M.J.E.: Smoothing and differentiation of data by simplified least squares procedures. Anal. Chem. 36, 1627 (1964).CrossRefGoogle Scholar
20Larson, A.C. and von Dreele, R.B.: General Structure Analysis System ( Los Alamos National Laboratory, Los Alamos, NM, 1994)Google Scholar
21Pfaff, G.: Synthesis and characterization of barium titanate. J. Mater. Sci. Lett. 10, 1059 (1991).CrossRefGoogle Scholar
22Arya, P.R., Jha, P. and Ganguli, A.K.: Synthesis, characterization and dielectric properties of nanometer-sized barium strontium titanates prepared by the polymeric citrate precursor method. J. Mater. Chem. 13, 415 (2003).CrossRefGoogle Scholar
23Sharma, P.K., Varadan, V.V. and Varadan, V.K.: Porous behavior and dielectric properties of barium strontium titanate synthesized by sol-gel method in the presence of triethanolamine. Chem. Mater. 12, 2590 (2000).CrossRefGoogle Scholar