Sains Malaysiana 44(7)(2015): 1003–1009

Subsolidus Solution and Oxide Ionic Conductivity of Nd-substituted Bismuth Yttria Fluorites

(Larutan Subpepejal 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

Diserahkan: 13 Ogos 2013/Diterima: 17 Mac 2015

ABSTRACT

Pure phase Bi_1.6Y_0.4-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 Bi_1.6Y_0.4-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. Bi_1.6Y_0.3Nd_0.1O₃ exhibited the highest oxide ion conductivity among the synthesised samples in Bi_1.6Y_0.4-xNdxO₃ solid solution.

Keywords: Fluorite; oxide ion conductivity; solid Solution; x-ray diffraction

ABSTRAK

Larutan pepejal Bi_1.6Y_0.4-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 Bi_1.6Y_0.4-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. Bi_1.6Y_0.3Nd_0.1O₃ mempunyai kekonduksian ion oksida yang paling tinggi antara fasa tulen yang dihasilkan dalam sistem larutan pepejal Bi_1.6Y_0.4-xNdxO₃.

Kata kunci: Fluolit; kekonduksian oksida; larutan pepejal; pembelauan sinar-x

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*Pengarang untuk surat-menyurat; email: tankarban@upm.edu.my