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Surface displacements and surface charges on Ba2CuWO6 and Ba2Cu0.5Zn0.5WO6 ceramics induced by local electric fields investigated with scanning-probe microscopy

Published online by Cambridge University Press:  03 March 2011

Ralf-Peter Herber
Affiliation:
Institute of Advanced Ceramics, Hamburg University of Technology, 21073 Hamburg, Germany
Gerold A. Schneider*
Affiliation:
Institute of Advanced Ceramics, Hamburg University of Technology, 21073 Hamburg, Germany
*
a)Address all correspondence to this author. e-mail: g.schneider@tu-harburg.de
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Abstract

Ba2CuWO6 (BCW) was first synthesized in the mid 1960s, and it was predicted to be a ferroelectric material with a very high Curie temperature of 1200 °C [N. Venevtsev and A.G. Kapyshev: New ferroelectrics. Proc. Int. Meet. Ferroelectr.1, 261 (1966)]. Since then, crystallographic studies were performed on the compound with the result that its crystal structure is centrosymmetric. Thus for principal reason, BCW cannot be ferroelectric. That obvious contradiction was examined in this study. Disk-shaped ceramic samples of BCW and Ba2Cu0.5Zn0.5WO6 (BCZW) were prepared. Because of the low electrical resistivity of the ceramics, it was not possible to perform a typical polariszation hysteresis loop for characterization of ferroelectric properties. Scanning electron microscopy investigations strongly suggest that the reason for the conductivity is found in the impurities/precipitations within the microstructure of the samples. With atomic force microscopy (AFM) in piezoresponse force microscopy (PFM) mode, it is possible to characterize local piezoelectricity by imaging the ferroelectric domains. Neither BCW nor BCZW showed any domain structure. Nevertheless, when local electric fields were applied to the surfaces of the ceramics topographic displacements, imaged with AFM, and surface charges, imaged with Kelvin probe force microscopy (KFM) and PFM, were measured and remained stable on the surface for the time of the experiment. Therefore BCW and BCZW are considered to be electrets and possibly relaxor ferroelectrics.

Type
Articles
Copyright
Copyright © Materials Research Society 2007

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References

REFERENCES

1Venevtsev, N. and Kapyshev, A.G.: New Ferroelectrics. Proc. Int. Meet. Ferroelectr. 1, 261 (1966).Google Scholar
2Blasse, G.: New compounds with perovskite-like structures. J. Inorg. Nucl. Chem. 27, 993 (1965).CrossRefGoogle Scholar
3Reinen, D. and Weitzel, H.: Crystal structures of Cu2+ containing oxidic elpasolites–Investigations of powders with neutron diffraction. Z. Anorg. Allg. Chem. 424, 31 (1976).CrossRefGoogle Scholar
4Jahn, H.A. and Teller, E.: Stability of polyatomic molecules in degenerate electronic states. I—Orbital degeneracy. Proc. R. Soc. London, A. 161, 220 (1937).Google Scholar
5Jahn, H.A.: Stability of polyatomic molecules in degenerate electronic states. II—Spin degeneracy. Proc. R. Soc. London, A. 164,117 (1938).Google Scholar
6Reinen, D. and Friebel, C.: Local and cooperative Jahn–Teller interactions in model structures. Struct. Bond. 37, 1 (1979).CrossRefGoogle Scholar
7Bokhimi, X.: Structure of the M2CuWO6 system, with M = Ba or Sr. Powder Diffr. 7, 228 (1992).CrossRefGoogle Scholar
8Porat, O. and Riess, I.: Defect chemistry of Cu2− yO at elevated temperatures. Part II: Electrical conductivity, thermoelectric power and charged point defects. Solid State Ionics 74, 229 (1994).Google Scholar
9Suda, S. and Aoyama, T.: Effects of lanthanum on the electrical conductivity of CuO ceramics. Jpn. J. Appl. Phys. 39, 3566 (2000).CrossRefGoogle Scholar
10Guthner, P. and Dransfeld, K.: Local poling of ferroelectric polymers by scanning force microscopy. Appl. Phys. Lett. 61, 1137 (1992).CrossRefGoogle Scholar
11Gruverman, A., Auciello, O., Ramesh, R., and Tokumoto, H.: Scanning force microscopy of domain structure in ferroelectric thin films: Imaging and control. Nanotechnology 8, A38 (1997).CrossRefGoogle Scholar
12Abplanalp, M., Eng, L.M., and Günter, P.: Mapping the domain distribution at ferroelectric surfaces by scanning force microscopy. Appl. Phys. A: Mater. Sci. Proc. 66, 231 (1998).CrossRefGoogle Scholar
13Eng, L.M., Abplanalp, M., and Günter, P.: Ferroelectric domain switching in tri-glycine sulphate and barium-titanate bulk single crystals by scanning force microscopy. Appl. Phys. A: Mater. Sci. Proc. 66, 679 (1998).CrossRefGoogle Scholar
14Eng, L.M., Güntherodt, H-J., Schneider, G.A., Köpke, U., and Muñoz-Saldaña, J.: Nanoscale reconstruction of surface crystallography from three-dimensional polarization distribution in ferroelectric barium-titanate ceramics. Appl. Phys. Lett. 74, 233 (1999).CrossRefGoogle Scholar
15Weaver, J.M.R. and Abraham, D.W.: High-resolution atomic force microscopy potentiometry. J. Vac. Sci. Technol. 9, 1559 (1991).CrossRefGoogle Scholar
16Jacobs, H.O., Knapp, H.F., and Stemmer, A.: Practical aspects of Kelvin probe force microscopy. Rev. Sci. Instrum. 30, 1756 (1999).CrossRefGoogle Scholar
17Kalinin, S.V. and Bonell, D.A.: Local potential and polarization screening on ferroelectric surfaces. Phys. Rev. B 63, 125411 (2001).CrossRefGoogle Scholar
18Electrets, edited by Sessler, G.M. (Springer Verlag, Berlin, Germany, 1980), p. 1.CrossRefGoogle Scholar