Sains Malaysiana 43(10)(2014): 1573–1582

Structural and Electrical Properties of Nb-substituted LiTa1-xNbxO₃

(Sifat Struktur dan Elektrik bagi LiTa1-xNbxO₃ yang Digantikan dengan Nb)

K.Y. BAK¹, K.B. TAN¹*, C.C. KHAW², Z. ZAINAL¹, P.Y. TAN¹ & M.P. CHON¹

¹Department of Chemistry, Faculty of Science, Universiti Putra Malaysia

43400 Serdang, Selangor, Malaysia

²Department of Mechanical and Material Engineering, Faculty of Engineering and Science

Universiti Tunku Abdul Rahman, 53300 Setapak, Kuala Lumpur, Malaysia

Diserahkan: 21 Ogos 2013/Diterima: 10 Februari 2014

ABSTRACT

Single phase LiTa1-xNbxO₃ solid solution with 0.00 ≤ x ≤ 1.00 was successfully synthesised via conventional solid-state method at 950°C for 24 h. These materials were refined and fully indexed with hexagonal crystal system, space group of R3c; lattice parameters, a ranging from 5.1410(6) Ǻ to 5.1471(3) Ǻ and c ranging from 13.7467(1) Ǻ to 13.8341(1) Ǻ; with α = β = 90° and γ = 120°. Variation of the lattice parameters in these materials was found to be negligibly small throughout the subsolidus solution. No thermal event was detected within the studied temperature range of 50 to 1000°C. The electrical properties of samples were characterised by AC impedance analyser, HP4192A at temperature ranging from room temperature to 850°C over a frequency range of 5 Hz to 13 MHz. LiTa1-xNbxO₃ materials exhibited bulk response with associated capacitances in the order of 10-12 F cm-1 and the temperature-dependent conductivities were found to increase with increasing temperatures. The results showed that LiTa1-xNbxO₃ samples were of typical ferroelectrics.

Keywords: Ferroelectric; impedance; solid solution; solid-state method

ABSTRAK

Larutan pepejal LiTa1-xNbxO₃ tulen dengan 0.00 ≤ x ≤ 1.00 telah berjaya disintesis melalui kaedah penyediaan keadaan pepejal pada 950°C selama 24 jam. Bahan-bahan tersebut dapat diindeks sepenuhnya dalam sistem kristal heksagon dengan kumpulan ruangan, R3c; nilai parameter kekisi, a, b dalam julat 5.1410(6) Ǻ ke 5.1471(3) Ǻ dan c dalam lingkungan 13.7467(1) Ǻ ke 13.8341(1) Ǻ; α = β = 90° dan γ = 120°. Perubahan parameter kekisi larutan pepejal LiTa1-xNbxO₃ didapati adalah terhad. Tiada sebarang keadaan terma dikesan daripada suhu 50 sehingga 1000°C. Sifat elektrik dicirikan dengan penganalisis AC impedans, HP4192A daripada suhu bilik hingga 850°C dalam julat frekuensi antara 5 Hz hingga 13 MHz. Bahan-bahan dalam siri larutan pepejal menunjukkan sifat pukal dengan kapasitan dalam tertib 10-12 F cm-1. Konduktiviti bagi sampel ini didapati meningkat dengan peningkatan suhu. Keputusan analisis menunjukkan siri larutan pepejal LiTa1-xNbxO₃ dengan 0.00 ≤ x ≤ 1.00 bersifat jenis bahan ferroelektrik.

Kata kunci: Ferroelektrik; impedans; kaedah penyediaan keadaan pepejal; larutan pepejal

RUJUKAN

Abrahams, S.C., Hamilton, W.C. & Reddy, J.M. 1966. Ferroelectric lithium niobate, single crystal neutron diffraction study. Journal of Physics and Chemistry of Solids 27: 1013-1018.

Ballman, A.A. & Brown, H. 1972. Ferroelectric domain reversal in lithium metatantalate. Ferroelectrics 4: 189-194.

Ekhelikar, S. & Bichile, G.K. 2004. Synthesis and characterization of (Bi2O3)1-x(Y2O3)x and (Bi2O3)1-x(Gd2O3)x solid solutions. Bulletin of Material Science 1: 19-22.

Evans, C.R., Stanley, S.M., Percival, C.J., McHalea, G. & Newton, M.I. 2006. Lithium tantalate layer guided plate mode sensors. Sensors and Actuators A 132: 241-244.

Gervais, F. & Fonseca, V. 1997. Handbook of Optical Constants of Solids, Lithium Tantalate (LiTaO3). Massachusettes: Academic Press. pp 777-805.

Gopalan, V., Sanford, N.A., Aust, J.A., Kitamura, K. & Furukawa, Y. 2001. Crystal growth, characterization, and domain studies in lithium niobate and lithium tantalate ferroelectrics (Vol 4, Chapter 2). In The Handbook of Advanced Electronic and Photonic Material and Devices, edited by Hari Singh Nalwa. Massachusettes: Academic Press. pp. 57-114.

Griffiths, P.R. & Haseth, J.A.D. 2007. Introduction to vibrational spectroscopy. In Fourier Transform Infrared Spectroscopy. Canada: John Wiley & Sons, Ltd. pp. 1-6.

He, X., Li, K., Liu, M., He, Y., Zhang, X., Zhao, Y. & Xue, D. 2008. An optical spectroscopy study of defects in lithium tantalate single crystals. Optics Communications 281: 2531-2534.

Hsu, R., Maslen, E.N. & Ishizawa, N. 1997. Synchrotron X-ray studies of LiNbO3 and LiTaO3. Acta Crystallographica, Section B: Structural Science 53: 420.

Irvine, J.T.S., Sinclair, D.C. & West, A.R. 1990. Electroceramics: Characterization by impedance spectroscopy. Advanced Materials 2: 132-138.

Iyi, N., Kitamura, K., Izumi, F., Yamamoto, J. K., Hayashi, T., Asano, H. & Kimura, S. 1992. Comparative study of defect structures in lithium niobate with different compositions. Journal of Solid State Chemistry 101: 340-352.

Kaczmarek, S.M., Swirkowicz, M., Jablonski, R., Lukasiewicz, T. & Kwasny, M. 2000. Growth and characterization of lithium tantalate single crystals doped with Ho, Tm, Nd, Yb, Pr and doped by diffusion with Cr and Cu. Journal of Alloys and Compounds 300-301: 322-328.

Karhunen, T., Lahde, A., Leskinen, J., Buchel, R. & Waser, O. 2011. Transition metal-doped lithium titanium oxide nanoparticles made using flame spray pyrolysis. ISRN Nanotechonology 2001, Article ID 180821: 1-6.

Khaw, C.C., Tan, K.B. & Lee, C.K. 2008. High temperature dielectric properties of cubic bismuth zinc tantalates. Ceramics International 35: 1473-1480.

Kitamura, K., Yamamoto, J.K., Iyi, N. & Kirnura, S. 1992. Stoichiometric LiNbO3 single crystal growth by double crucible Czochralski method using automatic power supply system. Journal of Crystal Growth 116: 327-332.

Mark, L. 2001. Dielectric constant and loss tangent in LiNbO3 crystals from 90 to 147 GHz. Applied Physic Letters 79: 1342-1345.

Megaw, H.D. 1968. A note on the structure of lithium niobate, LiNbO3. Acta Crystallographica, Section A 24: 583-588.

Palatnikova, M.N., Biryukovaa, I.V., Sidorova, N.V., Denisovb, A.V., Kalinnikova, V.T., Smithc, P.G.R. & Shurd, V.Y. 2006. Growth and concentration dependencies of rare-earth doped lithium niobate single crystals. Journal of Crystal Growth 291: 390-397.

Samuel, V., Gaikwad, A.B., Jadhav, A.D., Mirji, S.A. & Ravi, V. 2007. A novel technique to prepare LiNbO3 at low temperature. Materials Letters 61: 765-766.

Satapathy, S., Verma, P., Gupta, P.K., Mukherjee, C., Sathe, V.G. & Varma, K.B.R. 2011. Structural, dielectric and ferroelectric properties of multilayer lithium tantalate thin films prepared by sol-gel technique. Thin Solid Films 519: 1803-1808.

Seshadri, R., Smith, M.B., Page, K. & Steigerwald, M.L. 2008. Crystal structure and the paraelectric-to-ferroelectric phase transition to nanoscale BaTiO3. Journal of the American Chemical Society 130: 6955-6963.

Tan, M.Y., Tan, K.B., Zainal, Z., Khaw, C.C. & Chen, S.K. 2012. Subsolidus formation and impedance spectroscopy studies of materials in the (Bi2O3)1-x(Y2O3)x binary system. Ceramics International 38: 3403-3409.

Wachs, I.E., Briand, L.E., Jehng, J.M., Burcham, L. & Gao, X.T. 2000. Molecular structure and reactivity of the group V metal oxides. Catalysis Today 57: 323-330.

Wan, Y., Guo, X., Chen, J., Yuan, X., Chu, J. & Li, J. 2002. Optical properties of nonlinear potassium lithium niobate crystal. Journal of Crystal Growth 235: 248-252.

West, A.R. 1999. Crystal defects, non-stoichiometry and solid solutions. In Solid State Chemistry and It Applications. New Jersey: John Wiley & Sons, Ltd. pp 226-240.

Xue, D., Betzler, K. & Hesse, H. 2000. Dielectric properties of lithium niobate tantalate crystals. Solid State Communications 115: 581-585.

Yao, C.Y., Kao, T.H., Cheng, C.H. & Hurng, W.M. 1995. Studies of electrochemical properties of lithium cobalt oxide. Journal of Power Sources 54: 491-493.

Zhan, J., Liu, D., Du, W., Wang, Z., Wang, P., Cheng, H., Huang, B. & Jiang, M. 2011. Synthesis and characterization of high crystallinity, well-defined morphology stoichiometric lithium niobate nanocrystalline. Journal of Crystal Growth 318: 1121-1124.

*Pengarang untuk surat-menyurat; email: tankb@science.upm.my