フルテキストURL | 2008010259.pdf ( 249.4KB ) 公開日 2010-04-16
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タイトル | Structural determination of atomic substitution ratio in (K_<1-x>Rb_x)_2SeO_4 mixed crystal system |
作成者 | Sawae, Shinsuke
Nakashima, Terumi
Shigematsu, Hirotake
Kasano, Hironobu
Mashiyama, Hiroyuki
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作成者ヨミ | サワエ, シンスケ
ナカシマ, テルミ
シゲマツ, ヒロタケ
カサノ, ヒロノブ
マシヤマ, ヒロユキ
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作成者別表記 | 笠野, 裕修
増山, 博行
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作成者所属 | 山口大学大学院理工学研究科(理学)
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内容記述(抄録等) | In order to explain why Rb_2SeO_4 remains in normal phase down to 0 K while K_2SeO_4 transforms into the modulated phase at finite temperature, crystal structures of the mixed system have been refined at room temperature by X-ray single crystal analysis. Rb ion can be substituted for K ion with keeping the macroscopic symmetry of space group Pnam. Larger size of Rb ion occupies preferentially site 1, while smaller K ion prefers site 2. Here the atomic distance between an alkali ion and oxygen atoms is longer at site 1 than at site 2. The mean substitution ratio coincides with that from chemical analysis, however, the crystallographic structure analysis is only one method to determine the ratios at each site separately. A sublattice model is discussed to interpret the ion replacing effect on the phonon dispersion relation of the mixed crystal system. The hardening of the soft mode branch can be predicted by the change of interactions between the SeO_4 tetrahedrons if the alkali ions are replaced.
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本文言語 | eng
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著者キーワード | potassium selenate
rubidium selenate
mixed crystal
substitution ratio
structure analysis
phase transition
sublattice model
soft phonon dispersion
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資料タイプ | text |
ファイル形式 | application/pdf |
出版者 | The Physical Society of Japan
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出版者ヨミ | ニホン ブツリ ガッカイ
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NII資料タイプ | 学術雑誌論文 |
査読の有無 | 査読あり |
ISSN | 0031-9015
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NCID | AA00704814
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掲載誌名 | Journal of the Physical Society of Japan |
巻 | 74 |
号 | 10 |
開始ページ | 2748 |
終了ページ | 2753 |
発行日 | 2005 |
DOI | info:doi/10.1143/JPSJ.74.2748 |
関連情報URL(IsPartOf) | http://www.ipap.jp/jpsj/index.html
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権利関係 | Copyright c (2002)The Physical Society of Japan
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著者版/出版社版 | 著者版 |
リポジトリID | 2008010259 |
地域区分 | 山口大学
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URI | http://www.lib.yamaguchi-u.ac.jp/yunoca/handle/2008010259 |