Electrical conductivity of mullite-type Bi₂Al₄O₉ ceramics in air

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• 作者：S. Ohmann^a ; P. Fielitz^a ; ^{peter.fielitz@tu-clausthal.de} ; L. Dö ; rrer^a ; G. Borchardt^a ; Th.M. Gesing^b ; ^c ; ¹ ; R.X. Fischer^b ; C.H. Rü ; scher^c ; J.-C. Buhl^c ; K.-D. Becker^d ; H. Schneider^b ; ^e
• 关键词：Polycrystalline bismuth aluminate ; Electrical conductivity ; SrO doping
• 刊名：Solid State Ionics
• 出版年：2012
• 期刊代码：96_01672738
• 类别：ch
• 出版时间：15 March, 2012
• 卷：211
• 期：Complete
• 页码：46-50
• 文件大小：365 K

摘要

For the electrical conductivity of Bi₂Al₄O₉ based dense polycrystalline materials controversial data have been published in the literature. In this work samples with a nominal excess of Bi₂O₃ or SrO of up to 3 wt.%have been investigated in air using impedance spectroscopy. Both the results of this work and the literature data can be consistently interpreted on the basis of a simple model of the microstructure as consisting of Bi₂Al₄O₉ grains and a well conducting grain boundary film (Bi₂O₃ based in the case of a Bi₂O₃ excess) or a poorly conducting grain boundary film (SrO based in the case of a SrO excess), respectively. It turns out that the degree of SrO doping in Bi₂Al₄O₉ is much lower than suggested before. Thus an effect of SrO doping on the electrical conductivity of Bi₂Al₄O₉ can be ruled out.