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Dielectric relaxations, ultrasonic attenuation, and their structure dependence in Sr4(LaxNd1-x)2Ti4Nb6O30 tungsten bronze ceramics

Published online by Cambridge University Press:  31 January 2011

Xiao Li Zhu
Affiliation:
Laboratory of Dielectric Materials, Department of Material Science and Engineering, Zhejiang University, Hangzhou 310027, China
Xiang Ming Chen*
Affiliation:
Laboratory of Dielectric Materials, Department of Material Science and Engineering, Zhejiang University, Hangzhou 310027, China
Xiao Qiang Liu
Affiliation:
Laboratory of Dielectric Materials, Department of Material Science and Engineering, Zhejiang University, Hangzhou 310027, China
Xiao Guang Li
Affiliation:
Hefei National Laboratory for Physical Sciences at Microscale, Department of Physics, University of Science and Technology of China, Hefei 230026, China
*
a)Address all correspondence to this author. e-mail: xmchen59@zju.edu.cn
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Abstract

The dielectric anomalies and their structure dependence were evaluated and discussed in Sr4(LaxNd1-x)2Ti4Nb6O30 ceramics, together with the analysis of ultrasonic velocity shift and attenuation spectra in the low-temperature range. The room-temperature structure was confirmed as the tetragonal in space group P4bm for all compositions. One diffuse ferroelectric peak and three relaxor ferroelectric peaks corresponding to the commensurate/incommensurate modulation of oxygen octahedra, polar clusters of A-site ion ordering, and B-site ion ordering, respectively, were observed in the composition with x = 0.25. With decreasing the radius difference between A1- and A2-ions (increasing x), the dielectric relaxations, especially the one originating from the polar clusters of A-site ion ordering, tended to increase significantly and overlap the diffuse ferroelectric peak, which was completely overlapped for x ⩾ 0.75. This process just reflected the increased disordering degree of both A- and B-site ions, and the analysis of ultrasonic attenuation strongly supported the above conclusions on dielectric relaxations and their structural origins. The ultrasonic attenuation peak at approximately 100 K corresponded to the freezing process of the dielectric relaxations, and the fluctuation with composition of the ultrasonic attenuation peaks between 150 and 260 K suggested the possible structure variation.

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Articles
Copyright
Copyright © Materials Research Society 2008

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References

REFERENCES

1Mori, S., Yamamoto, N., Koyama, Y., Uesu, Y.: Low-temperature transition in barium sodium niobate Ba2NaNb5O15. Phys. Rev. B: Condens. Matter 55, 11212 1997Google Scholar
2Xie, R.J., Akimune, Y., Matsuo, K., Sugiyama, T., Hirosaki, N., Sekiya, T.: Dielectric and ferroelectric properties of tetragonal tungsten bronze Sr2–xCaxNaNb5O15 (x = 0.05–0.35) ceramic. Appl. Phys. Lett. 80, 835 2002Google Scholar
3Zheng, X.H., Chen, X.M.: Crystal structure and dielectric properties of ferroelectric ceramics in the BaO-Sm2O3-TiO2-Nb2O5 system. Solid State Commun. 125, 449 2003Google Scholar
4Zheng, X.H., Chen, X.M.: Dielectric ceramics with tungsten-bronze structure in the BaO–Nd2O3–TiO2–Nb2O5 system. J. Mater. Res. 17, 1664 2002Google Scholar
5Cross, L.E.: Relaxor ferroelectrics. Ferroelectrics 76, 241 1987Google Scholar
6Kirk, C.A., Stennett, M.C., Reaney, I.M., West, A.R.: A new relaxor ferroelectric, Ba2LaTi2Nb3O15. J. Mater. Chem. 12, 2609 2002Google Scholar
7Miles, G.C., Stennett, M.C., Reaney, I.M., West, A.R.: Temperature-dependent crystal structure of ferroelectric Ba2LaTi2Nb3O15. J. Mater. Chem. 15, 798 2005CrossRefGoogle Scholar
8Zhu, X.L., Chen, X.M., Liu, X.Q., Yuan, Y.: Dielectric characteristics and diffuse ferroelectric phase transition in Sr4La2Ti4Nb6O30 tungsten bronze ceramics. J. Mater. Res. 21, 1787 2006Google Scholar
9Bovtun, V., Kamba, S., Veljko, S., Nuzhnyy, D., Knizek, K., Savinov, M., Petzelt, J.: Relaxor-like behavior of lead-free Sr2LaTi2Nb3O15 ceramics with tetragonal tungsten bronze structure. J. Appl. Phys. 101, 054115 2007Google Scholar
10Zhu, X.L., Chen, X.M., Liu, X.Q.: Dielectric abnormity of Sr4Nd2Ti4Nb6O30 tungsten bronze ceramics over a broad temperature range. J. Mater. Res. 22, 2217 2007Google Scholar
11Sun, Y.H., Chen, X.M., Zheng, X.H.: Tungsten bronze type dielectrics in SrO-Sm2O3-TiO2-Nb2O5 system and their dielectric anomaly. J. Appl. Phys. 96, 7435 2004Google Scholar
12Neurgaonkar, R.R., Oliver, J.R., Cory, W.K., Cross, L.E., Vieland, D.: Piezoelectricity in tungsten bronze crystals. Ferroelectrics 160, 265 1994CrossRefGoogle Scholar
13Levin, I., Stennett, M.C., Miles, G.C., Woodward, D.I., West, A.R., Reaney, I.M.: Coupling between octahedral tilting and ferroelectric order in tetragonal tungsten bronze-structured dielectrics. Appl. Phys. Lett. 89, 122908 2006Google Scholar
14Stennett, M.C., Reaney, I.M., Miles, G.C., Woodward, D.I., West, A.R., Kirk, C.A., Levin, I.: Dielectric and structural studies of Ba2MTi2Nb3O15 (BMTNO15, M = Bi3+, La3+, Nd3+, Sm3+, Gd3+) tetragonal tungsten bronze-structured ceramics. J. Appl. Phys. 101, 104114 2007Google Scholar
15Chen, X.M., Yang, J.S.: Dielectric characteristics of ceramics in BaO–Nd2O3–TiO2–Ta2O5 system. J. Eur. Ceram. Soc. 19, 139 1999Google Scholar
16Chen, X.M., Xu, Z.Y., Li, J.: Dielectric ceramics in the BaO–Sm2O3–TiO2–Ta2O5 quaternary system. J. Mater. Res. 15, 125 2000Google Scholar
17Chen, X.M., Lu, G.L., Yang, J.S., Wu, Y.J.: Some tungsten-bronze compounds in the BaO-Nd2O3-TiO2-Ta2O5 system. J. Solid State Chem. 148, 438 1999CrossRefGoogle Scholar
18Viehland, D., Jang, S.J., Cross, L.E.: Freezing of the polarization fluctuations in lead magnesium niobate relaxors. J. Appl. Phys. 68, 2916 1990Google Scholar
19Cheng, Z.-Y., Katiyar, R.S., Yao, X., Guo, A.: Dielectric behavior of lead magnesium niobate relaxors. Phys. Rev. B 55, 8165 1997Google Scholar
20Zhu, X.L., Wu, S.Y., Chen, X.M.: Dielectric anomalies in (BaxSr1−x)4Nd2Ti4Nb6O30 ceramics with various radius differences between A1- and A2-site ions. Appl. Phys. Lett. 91, 162906 2007Google Scholar
21Rodriguez-Carvajal, J.: Recent developments of the program FULLPROF in commission on powder diffraction (1μ Cr). Newsletter 26, 12 2001Google Scholar
22Hornebecq, V., Elissalde, C., Weill, F., Villesuzanne, A., Menetrier, M., Ravez, J.: Study of disorder in a tetragonal tungsten bronze ferroelectric relaxor: A structural approach. J. Appl. Crystallogr. 33, 1037 2000Google Scholar
23Qu, J.F., Liu, Y., Wang, F., Xu, X.Q., Li, X.G.: Ultrasonic study of the charge-stripe phase in La1.88–yNdySr0.12CuO4. Phys. Rev. B 71, 094503 2004Google Scholar
24Qu, J.F., Zhang, Y.Q., Lu, X.L., Xiang, X.Q., Liao, Y.L., Li, G., Li, X.G.: Ultrasonic study on magnetic-field-induced stripe order in La1.88Sr0.12–xBaxCuO4. Appl. Phys. Lett. 89, 162508 2006Google Scholar
25Moreno-Gobbi, A., Perez, M., Paolini, G., Negreira, C.A., Garcia, D., Eiras, J.A.: Ultrasound studies of phase transitions in tungsten bronze ferroelectric materials. J. Alloys Compd. 310, 29 2000Google Scholar
26Zhu, X.L., Chen, X.M., Li, X.G.: Dielectric relaxation and ultrasonic attenuation of Sr4La2Ti4Nb6O30 tungsten bronze ceramics. Appl. Phys. Lett. 90, 182905 2007Google Scholar