کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1450251 988728 2006 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Extended X-ray absorption fine structure analysis of (Ca,Nd)(Ti,Al)O3 perovskite ceramics used in cellular base stations
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Extended X-ray absorption fine structure analysis of (Ca,Nd)(Ti,Al)O3 perovskite ceramics used in cellular base stations
چکیده انگلیسی

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.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 54, Issue 9, May 2006, Pages 2305–2309
نویسندگان
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