Distribution of Fe'3+' in a synthetic (Ca,Na)2(Mg,Fe'3+')Si2O7-melilite: '57'Fe Moessbauer and X-ray Rietveld studies
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Accession number;06A0010670
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| Title;Distribution of Fe'3+' in a synthetic (Ca,Na)2(Mg,Fe'3+')Si2O7-melilite: '57'Fe Moessbauer and X-ray Rietveld studies |
| Author;
AKASAKA MASAHIDE
(Shimane Univ., Matsue, Jpn)
NAGASHIMA MARIKO
(Shimane Univ., Matsue, Jpn)
MAKINO KUNIAKI
(Shinshu Univ., Matsumoto, Jpn)
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Journal Title;J Mineral Petrol Sci
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Journal Code:G0150B
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ISSN:1345-6296
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VOL.100;NO.6;PAGE.229-236(2005)
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| Figure&Table&Reference;FIG.4, TBL.4, REF.38 |
| Pub. Country;Japan |
| Language;English |
| Abstract;Crystal structure and the '57'Fe Moessbauer spectrum of synthetic (Ca1.53Na0.47)(Mg0.52Fe0.49'3+')Si1.99O7-melilite have been investigated to confirm the location of Fe'3+' at the T1 site, and to evaluate the effect of an incommensurate structure on '57'Fe Moessbauer hyperfine parameters. A conventional Rietveld refinement with occupancies of Ca(W), Na(W), Mg(T1), Fe'3+'(T1) and Si(T2) fixed to 0.765, 0.235, 0.515, 0.485 and 2.00, respectively, converged well with an Rwp (R-weighted pattern) of 13.14% and a goodness-of-fit of 1.337, indicating exclusive Fe'3+' distribution at the T1 site. However, the Moessbauer spectrum consists of two doublets with an isomer shift of 0.19mm/s and quadrupole splitting of 0.75 and 1.04mm/s, which can be attributed to Fe'3+' at the T1 site. There are two sorts of T1 site with distinguishable distortion in the synthetic Na-Fe'3+'-melilite, which might be attributed to the existence of an incommensurate phase at room temperature. (author abst.) |
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