کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1450251 | 988728 | 2006 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Extended X-ray absorption fine structure analysis of (Ca,Nd)(Ti,Al)O3 perovskite ceramics used in cellular base stations Extended X-ray absorption fine structure analysis of (Ca,Nd)(Ti,Al)O3 perovskite ceramics used in cellular base stations](/preview/png/1450251.png)
The local structural environments for Ca, Nd and Ti atoms in Ca0.7Nd0.3Ti0.7Al0.3O3 ceramics were studied at 298 K using extended X-ray absorption fine structure (EXAFS) analysis. The theoretical EXAFS spectra were in excellent agreement with experimental EXAFS data. There was very good agreement between EXAFS-derived distances and X-ray data for Ti (all three shells), but for Ca and Nd the EXAFS distances for the first co-ordination shell (Ca–O and Nd–O) were significantly less than values obtained from X-ray analysis and Shannon’s ionic radii; also, co-ordination numbers were inconsistent with X-ray results for Ca and Nd. The similarity in the data for Ca and Nd confirms that the cations sit in a shared site, where there is large disorder in (Ca/Nd)–O distances. Bond valence sums for the Ti site were abnormally high, indicating compression of the site, possibly as a result of compositionally induced strain.
Journal: Acta Materialia - Volume 54, Issue 9, May 2006, Pages 2305–2309