Sains Malaysiana 39(3)(2010): 479–484

 

 

Effect of Zirconium Substitution on the Phase Formation and Microstructure of BaCeO3

(Kesan Penggantian Zirkonium ke Atas Pembentukan Fasa danMikrostruktur BaCeO3)

 

 

N. Osman1*, I.A. Talib2 & H. A. Hamid1

1Faculty of Applied Sciences, Universiti Teknologi MARA 02600 Arau, Perlis, Malaysia

 

2Faculty of Science & Technology, Universiti Kebangsaan Malaysia 43600 Bangi, Selangor Malaysia

 

Diserahkan: 22 Jun 2009 / Diterima: 10 September 2009

 

ABSTRACT

 

Polycrystalline compounds of Ba(Ce1-xZrx)0.95Yb0.05O2.975 (0.20 ≤ x ≤ 0.40) were prepared by the conventional solid state reaction method. All the samples exhibited the orthorhombic structure of BaCeO3. The particle size and morphology of the powdered samples were found to change gradually with Zr content. The sample with x=0.40 showed more agglomerates of about 10.0 μm in size, and the particles constituting the agglomerates were smaller than 1.0 μm. For the polished and etched pelleted samples, only the x=0.20 sample showed clear grain shapes with sizes in the range of 1.0 to 3.0 μm. By increasing the Zr content to more than 20 mol%, the grain sizes became less pronounced and smaller. The deficiency of Ba that caused the formation of a Ce, Zr and Yb-rich sample was detected by energy dispersive X-ray measurement. Ba deficiency was attributed to the loss of BaO during the calcination and sintering processes.

 

Keywords: Cerate-zirconate; microstructure; oxides ceramic; phase formation

 

ABSTRAK

 

Polihablur sebatian polihablur Ba(Ce1-xZrx)0.95Yb0.05O2.975 (0.20 ≤ x ≤ 0.40) telah disediakan melalui kaedah tindak balas keadaan pepejal konveksional. Semua sampel menunjukkan struktur ortorombik bagi BaCeO3. Saiz zarah dan morfologi serbuk sampel didapati berubah dengan kandungan Zr. Sampel dengan x=0.40 mempamerkan banyak aglomerat yang bersaiz lebih kurang 10.0 μm dan zarah-zarah yang membentuk aglomerat tersebut bersaiz lebih kecil daripada 1.0 μm. Untuk pelet yang digilap dan dipunarkan, hanya sampel x=0.20 menunjukkan bentuk butiran yang jelas dengan saiz antara 1.0 hingga 3.0 μm. Dengan penambahan kandungan Zr lebih daripada 20 %mol, saiz butiran menjadi kurang jelas dan semakin mengecil. Kekurangan unsur Ba yang dikesan menggunakan spektroskopi sebaran tenaga sinar-X telah menyebabkan pembentukan fasa yang kaya dengan Ce, Zr and Yb di dalam sampel kajian. Kekurangan unsur Ba ini adalah disebabkan oleh kehilangan BaO semasa proses pengkalsinan dan persinteran.

 

Kata kunci: Mikrostruktur; pembentukan fasa; serat-zirkonat; seramik oksida

 

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*Pengarang untuk surat-menyurat; email: fisha@perlis.uitm.edu.my

 

 

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