(Sr,Ca) 3Sn2O7とそれ以上のハイブリッド不適切なフェロ電気:n = 2のラドルズデン-ポッパー相におけるフェロ電気移行温度と耐性因子の普遍的な関係
Suguru Yoshida1, Hirofumi Akamatsu, Ryosuke Tsuji1
1Department of Material Chemistry, Graduate School of Engineering , Kyoto University , Katsura Nishikyo-ku , Kyoto 615-8510 , Japan.
Journal of the American Chemical Society
|October 24, 2018
まとめ
ハイブリッドの不適切なフェロ電気は ジオメトリックの歪みを用いて 極化を作り出します 研究者らは,キュリー温度 (TC) とゴールドシュミット耐性因子 (t) の間の線形関係を発見した.
科学分野:
- 材料科学
- 固体物理学
- クリスタルグラフィー
背景:
- ハイブリッド不適切なフェロ電気は,極化のための幾何学的歪みを活用し,新しいフェロ電気およびマルチフェロ材料への経路を提供します.
- グループ理論と第一原理を用いた現在の設計方法は,結晶の対称性を正確に予測しますが,キュリー温度 (TC) のような重要なパラメータに苦労します.
研究 の 目的:
- TCとGoldschmidt耐性因子 (t) の間の予測的,定量的な関係をハイブリッド不適切なフェロエレクトリックで確立する.
- Ruddlesden-Popper (RP) システムにおけるフェロ電気的移行に対する純粋な幾何学的な (イオンサイズ) 効果を調査する.
主な方法:
- n = 2 Ruddlesden-Popper (RP) A3B2O7システム,特に (Sr1-xCax) 3Sn2O7を,幾何学的効果を研究するために使用した.
- 電子的なフェロ電気的歪曲メカニズム (例えば,d0と6s2カチオン) を欠く材料に焦点を当てた.
- 実験的に様々な組成物のTCを決定し,耐性因子 (t) と相関した.
主要な成果:
- Sr3Sn2O7に対してTC = 410 Kでフェロ電気からパラ電気への移行が観察された.
- TCは,Ca2+の含有量増加 (tの減少) により,線形的に800Kまで増加することを発見した.
- この線形TC-t関係が,すべての既知のA3B2O7ハイブリッド不適切なフェロエレクトリックに適用されることを実証した.
結論:
- イオンサイズ不一致に基づいて,TCと結晶化学記述子であるゴールドシュミット耐性因子 (t) の間の予測的相関を確立した.
- この発見は,ハイブリッド不適切なフェロエレクトリックでTCを推定するためのガイドラインを提供します.
- 既存のグループ理論と第一原理の設計アプローチを補完し,新しい鉄電気材料を発見します.
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