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Sains Malaysiana 44(7)(2015): 1003–1009 Subsolidus Solution
and Oxide Ionic Conductivity of Nd-substituted
Bismuth Yttria Fluorites (Larutan
Pepejal dan
Kekonduksian Ion Oksida bagi Fluorit Bismuth Yittria yang Digantikan dengan Nd) N. RAHMAN1,
K.B.
TAN1*,
Z.
ZAINAL1,
C.C.
KHAW2
& M.P. CHON1 1Department of Chemistry,
Faculty of Science, Universiti Putra Malaysia,
43400 Serdang, Selangor Darul Ehsan, Malaysia 2Department of Mechanical
and Material Engineering, Faculty of Engineering and Science Universiti Tunku Abdul Rahman, 53300 Setapak,
Kuala Lumpur, Malaysia Received: 13 August
2013/Accepted: 17 March 2015 ABSTRACT Pure phase Bi1.6Y0.4-xNdxO3 solid
solution with x = 0.00, 0.10 and 0.20 was successfully synthesised
via conventional solid state method at 850°C in 21 h. The materials
were refined and fully indexed with space group Fm-3m and lattice
parameters, a ranging from 5.5124(1) Å to 5.5289(4) Å. Variation
of the lattice parameters of these materials were found in an almost
linear correlation with increasing Nd2O3 dopant
concentration. Thermal analysis of Bi1.6Y0.4-xNdxO3 solid
solution showed no thermal event that associated with any phase
transition or weight loss within the studied temperature range of
35 to 900°C. The electrical properties of the samples were investigated
by ac impedance analyser, HP4192
at temperature ranging from 25 to 800°C over frequency of 5 Hz to
13 MHz. Bi1.6Y0.3Nd0.1O3
exhibited the highest oxide ion conductivity
among the synthesised samples in Bi1.6Y0.4-xNdxO3 solid
solution. Keywords: Fluorite; oxide ion
conductivity; solid Solution; x-ray diffraction ABSTRAK Larutan pepejal Bi1.6Y0.4-xNdxO3 berfasa tulen dengan
x = 0.00, 0.10 dan 0.20 telah
berjaya dihasilkan
melalui kaedah keadaan pepejal pada suhu 850°C dalam tempoh 21 jam. Bahan-bahan berkenaan telah dihalusi dan diindeks sepenuhnya
dengan kumpulan
ruangan Fm-3m dengan nilai parameter kekisi dalam lingkungan 5.5124(1) Å hingga 5.5289(4) Å. Parameter kekisi
bahan-bahan berkenaan
menunjukkan kolerasi yang berkadar terus dengan penambahan Nd2O3 yang
didopkan. Analisis terma bagi larutan pepejal Bi1.6Y0.4-xNdxO3 tidak menunjukkan sebarang acara terma yang berkaitan dengan peralihan fasa atau penurunan berat dalam suhu
kajian dari
35 hingga 900°C. Sifat elektrik dicirikan pada suhu ~ 30 hingga 800°C dengan menggunakan penganalisis AC
impedans, HP4192 dalam
julat frekunsi
daripada 5 Hz hingga 13 MHz. Bi1.6Y0.3Nd0.1O3 mempunyai kekonduksian ion oksida yang paling tinggi antara fasa tulen
yang dihasilkan dalam
sistem larutan pepejal Bi1.6Y0.4-xNdxO3. Kata kunci: Fluolit;
kekonduksian oksida;
larutan pepejal; pembelauan sinar-x REFERENCES
Boivin,
J.C. 2001.
Structural and electrochemical features of fast
oxide ion conductors. International Journal of Inorganic
Materials 3: 1261-1266. Boivin,
J.C. & Mairesse, G. 1998. Recent material developments in fast ionic conductors. Chemistry of Materials 10: 2870- 2888. Harwig,
H.A. & Gerads, A.G. 1979. The polymorphism of bismuth sesquioxide.
Thermochimica Acta
28: 121-131. Harwig,
H.A. & Gerads, A.G. 1978. Electrical properties of α, β, γ, and δ phases
of bismuth sesquioxide. Journal
of Solid State Chemistry 26: 265-274. Irvine,
J.T.S., Sinclair, D.C. & West, A.R. 1990. Electroceramics: Characterization by impedance spectroscopy.
Advanced Materials 2: 132-138. Khaw,
C.C., Tan, K.B. & Lee, C.K. 2009. High temperature dielectric properties
of cubic bismuth zinc tantalate. Ceramics
International 35: 1473-1480. Kruidhof,
H., De Vries, K.J. & Birggraaf,
A.J. 1990.
Thermochemical stability and nonstoichiometry
of yttria-stabilized bismuth oxide solid
solutions. Solid State Ionics 37: 213-215. Mairesse, G. 1993. In fast ion transport in solids, edited by Scrosati,
B. Amsterdam: Kluver. p.
271. Sammes,
N.M., Tompsett, G.A., Nafe,
H. & Aldinger, F. 1999. Bismuth based
oxide electrolytes-structure and ionic conductivity. Journal
of the European Ceramic Society 19: 1801-1826. Shannon, R.D. 1976.
Revised effective ionic radii and systematic studies
of interatomic distances in halides and chalcogenides. Acta
Crystallography A 32: 751-767. Stambouli,
A.B. & Traversa, E. 2002. Solid oxide fuel
cells (SOFCs): A review of an environmentally clean and efficient
source of energy. Renewable and Sustainable Energy Reviews 6:
433-455. Sinclair,
D.C. & West, A.R. 1989. Impedance and modulus spectroscopy of
semiconducting BaTiO3 showing
positive temperature coefficient of resistance. Journal of Applied
Physics 66: 3850-3856. Takahashi,
T. & Iwahara, H. 1978. Oxide ion conductors
based on bismuthsesquioxide. Materials
Research Bulletin 13: 1447-1453. Takahashi,
T., Iwahara, H. & Arao,
T. 1975.
High oxide ion conduction in sintered oxides of
the system Bi2O3-Y2O3.
Journal of Applied Electrochemistry 5: 187-195. 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.
Watanabe,
A. 1996.
Phase equlibria in the system Bi2O3-Y2O3:
no possibility of δ-Bi2O3 stabilization.
Solid State Ionics 86-88: 1427-1430. Watanabe,
A. & Kikuchi, T. 1986. Cubic hexagonal of yttria-stabilized
δ-bismuth sesquioxide, Bi2-2xY2x
O3 (x
= 0.215- 0.235). Solid State Ionics 21: 287-291. West, A.R. 1999. Crystal defects,
non-stoichiometry and solid solutions. In Solid State Chemistry
and It Applications. New York: John Wiley & Sons, Ltd. pp.
226-240. Yashima, M. & Ishimura, D. 2003.
Crystal structure and disorder of the fast oxide
ion conductor cubic Bi2O3,
Chemical Physics Letter 378: 395-399. *Corresponding author;
email: tankarban@upm.edu.my
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