高圧で高温でC60のトポケミカル3Dポリメリゼーション
Shoji Yamanaka1, Nagesh S Kini, Akira Kubo
1Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
Journal of the American Chemical Society
|March 12, 2008
まとめ
高圧・高温処理により,フラーレンC60を3Dポリマーに変形させ,硬さは立方ボロンニトリドに匹敵する. この新しい材料は,半導体帯構造を示し,潜在的な電子アプリケーションを示しています.
科学分野:
- 材料科学 材料科学とは
- 固体物理 固体物理学
- 化学 化学は化学です.
背景:
- フルレレン,特にC60は,ユニークな分子構造を持つ炭素のアロトロップである.
- C60の高圧および高温の振る舞いを調査することで,性能が向上した新材料が開発される可能性があります.
研究 の 目的:
- 極端な条件下でC60の3次元 (3D) ポリマーを合成し,特徴づけること.
- 結果となるC60ポリマーの構造的,機械的,電子的性質を決定する.
主な方法:
- フラーレンのC60単体結晶を500~600°Cで15GPaまで圧縮する.
- マイクロビッカースの硬さテスト.
- シングルクリスタルX線構造分析.
- アブ・イニシオ幾何学最適化と分子動力学の計算.
- バンド構造の計算と電気伝導性の測定.
主要な成果:
- 高マイクロビッカース硬度 (4500 kg/mm2) を有するC60の面中心立方 (fcc) 段階の形成.
- [2+2]サイクロアディションの3DC60ポリマー構造の識別,アビニシオ計算では [3+3]サイクロアディションのロンボエドール (R) 構造が示唆されているが.
- fcc相は,ロンボエドール相の平均構造である.
- 3D C60ポリマー (R構造) は,0.25 eVの活性化エネルギーで半導体特性を示しています.
結論:
- 高圧と高温の合成により,特殊な硬さを持つ新しい3D C60ポリマーが得られます.
- 構造はロンボエドール形であり,fcc形は平均表現である.
- この材料は半導体としての振る舞いを示し,電子機器で使用するための道を切り開いている.
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