2025-09-23 中国科学院(CAS)
編集注記：
(111)結晶面とは、結晶構造を表す「ミラー指数（Miller indices）」で表記された結晶面の一つです。ダイヤモンドやシリコンのような結晶は、原子が三次元的に規則正しく並んでいます。このとき、結晶を切断したり観察したりする基準となる面を「結晶面」と呼び、ミラー指数で表します。
- (100)面：立方体の各面に対応する面。原子配列が比較的単純で平坦。
- (110)面：立方体の辺を含む面。原子の並びが溝状に見える。
- (111)面：立方体の体対角線に垂直な面。原子が最も密に詰まった「密充填面」であり、結晶の安定性や物性に大きく関わる。
ダイヤモンド構造においては、(111)面は原子密度が高いが、特定条件下で歪みやすく、電場や熱によって破壊の起点になりやすいとされています。
＜関連情報＞
- https://english.cas.cn/newsroom/research_news/phys/202509/t20250925_1055331.shtml
- https://www.cell.com/cell-reports-physical-science/fulltext/S2666-3864(25)00442-4
電気破壊によるダイヤモンドの破壊メカニズム Failure mechanism of diamond under electrical breakdown
Zengyu Yan ∙ Guanyu Zheng ∙ Haochen Zhang ∙ … ∙ Duojun Wang ∙ Qingbo Yan ∙ Guangchao Chen
Cell Reports Physical Science Published:September 16, 2025
DOI:https://doi.org/10.1016/j.xcrp.2025.102843
Graphical abstract
Highlights
- In situ observation of diamond failure under electrical breakdown
- Failure mechanism of diamond along the (111) plane under stress
- The transformation of diamond into amorphous carbon under electrical breakdown
- Comparison of thermal stability of various diamond-exposed surfaces
Summary
Diamond holds immense potential for high-power electronics due to its ultrahigh breakdown field strength and exceptional thermal conductivity. However, material failure under extreme electric fields necessitates a fundamental understanding of crystallographic-orientation-dependent breakdown mechanisms. In this work, we designed and performed in situ breakdown experiments on single-crystal diamond within the transmission electron microscopy (TEM) mode, achieving controlled breakdown under real-time observation. Comprehensive structural, compositional, and stress analyses revealed that failure initiates preferentially along the (111) plane, driven by sequential lattice distortion and amorphization. Molecular dynamics (MD) simulations further elucidated atomic-scale degradation pathways, demonstrating anisotropic thermal stability across low-index crystallographic orientations. The (111)-oriented surface exhibited pronounced structural collapse under thermal stress, while (100) and (110) planes maintained integrity until higher thresholds. This work’s integrated experimental-computational approach clarifies crystallographic dependency in diamond breakdown, offering critical insights for designing robust diamond devices.
