SrBi2Ta2O9 (SBT) samples have been prepared by sol-gel technique with varying amount of excess Bi added to the starting composition. The excess Bi profoundly affects the dielectric and ferroelectric properties. The dielectric constant (ε) and remnant polarization increases from 80 and 1.4 μ C/cm2 for SBT with 1 mole % of excess Bi to 120 and 6.5 μ C/cm2 for SBT with 20 mole % of excess Bi. The Raman spectra, scanning electron microscopy images and the x-ray diffraction analysis show an improvement in structural quality of the samples with addition of excess Bi to the starting composition. The effect of Mn doping has also been studied by preparing SrBi2Ta2-x Mnx O9 (SBT-Mn) with x = 0–0.1. In the case of SBT-Mn samples, the XRD spectra revealed an unknown phase when x > 0.025. However, Raman spectra reveal the retention of Bi layer structure for all Mn compositions, with possibly small distortions. With Mn addition, ε increased to ∼ 140 for x < 0.005, but decreased to ≤ 120 when x > 0.015. The value of ε is independent of frequency from 60 to 85 kHz for all compositions of Mn. The effect of Mn addition resulted in a strong decrease in the area of the hysteresis loops.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
P.C. Joshi, S. O. Ryu, X. Zhang and S. B. Desu, Appl. Phys. Lett. 70, 1080 (1997).
C. A. Araujo, J. D. Cuchiaro, M. C. Scott and L. D. McMillan, Nature 374, 627 (1995).
E. C. Subbarao, Phys. Rev. 122, 804 (1961).
E. C. Subbarao, J. Phys. Chem. Solids 23, 665 (1962).
G. A. Smolenskii, V.A. Isupov and A. I. Agranovskaya, Sov. Phys.-Solid State 3, 651 (1961).
R. E. Newnham, R. W. Wolfe, R.S. Horsey, F. A. Diaz-Colon, M. I. Kay, Mater Res. Bull. 8, 1183 (1973).
A.D. Rae, J.G. Thompson and R.L. Withers, Acta Crystallogr. Sect. B 48, 418 (1992).
P. S. Dobal and R. S. Katiyar, J. Raman Spectrosc. 33, 405 (2002) and references therein.
This work was supported by the Postgraduate Education and Research Program in Chemistry, Mahidol University, Thailand, the Office of Vice President for Research at the University of Michigan, Ann Arbor, and the Center for Smart Sensors and Integrated Microsystems at Wayne State University.
About this article
Cite this article
Sookawee, T., Pdungsap, L., Winotai, P. et al. Effect of Mn Doping on the Structural and Ferroelectric properties of SrBi2Ta2O9. MRS Online Proceedings Library 848, 320–325 (2004). https://doi.org/10.1557/PROC-848-FF6.19