Three-step formation of diamonds in shock-compressed hydrocarbons: Dissociation, species separation, and nucleation

Chen Bo; Zeng Qiyu; Yu Xiaoxiang; Chen Jiahao; Zhang Shen; Kang Dongdong; Dai Jiayu

doi:10.1063/5.0273729

Volume 11 Issue 1

Jan. 2026

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Chen Bo, Zeng Qiyu, Yu Xiaoxiang, Chen Jiahao, Zhang Shen, Kang Dongdong, Dai Jiayu. Three-step formation of diamonds in shock-compressed hydrocarbons: Dissociation, species separation, and nucleation[J]. Matter and Radiation at Extremes, 2026, 11(1): 017603. doi: 10.1063/5.0273729

Citation:

Chen Bo, Zeng Qiyu, Yu Xiaoxiang, Chen Jiahao, Zhang Shen, Kang Dongdong, Dai Jiayu. Three-step formation of diamonds in shock-compressed hydrocarbons: Dissociation, species separation, and nucleation[J]. Matter and Radiation at Extremes, 2026, 11(1): 017603. doi: 10.1063/5.0273729

Citation:

Chen Bo, Zeng Qiyu, Yu Xiaoxiang, Chen Jiahao, Zhang Shen, Kang Dongdong, Dai Jiayu. Three-step formation of diamonds in shock-compressed hydrocarbons: Dissociation, species separation, and nucleation[J]. Matter and Radiation at Extremes, 2026, 11(1): 017603. doi: 10.1063/5.0273729

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Three-step formation of diamonds in shock-compressed hydrocarbons: Dissociation, species separation, and nucleation

doi: 10.1063/5.0273729

Chen Bo^{1, 2, 3
,},
Zeng Qiyu^{1, 2, 3
,},
Yu Xiaoxiang^{1, 2, 3
,},
Chen Jiahao^{1, 2, 3},
Zhang Shen^{1, 2, 3
,},
Kang Dongdong^{1, 2, 3
,},
Dai Jiayu^{1, 2, 3
,
,
,}

1.
College of Science, National University of Defense Technology, Changsha 410073, China
2.
Hunan Key Laboratory of Extreme Matter and Applications, National University of Defense Technology, Changsha 410073, China
3.
Hunan Research Center of the Basic Discipline for Physical States, National University of Defense Technology, Changsha 410073, China

More Information

Corresponding author: a)Author to whom correspondence should be addressed: jydai@nudt.edu.cn
Received Date: 2025-04-01
Accepted Date: 2025-10-30

Available Online: 2026-01-01

Publish Date: 2026-01-01

Abstract

Abstract

The accumulation and circulation of carbon and hydrogen contribute to the chemical evolution of ice giant planets. Species separation and diamond precipitation have been reported in carbon–hydrogen systems and have been verified by static and shock compression experiments. Nevertheless, the dynamic formation processes underlying these phenomena remain insufficiently understood. In combination with a deep learning model, we demonstrate that diamonds form through a three-step process involving dissociation, species separation, and nucleation processes. Under shock conditions of 125 GPa and 4590 K, hydrocarbons decompose to give hydrogen and low-molecular-weight alkanes (CH₄ and C₂H₆), which escape from the carbon chains, resulting in C/H species separation. The remaining carbon atoms without C–H bonds accumulate and nucleate to form diamond crystals. The process of diamond growth is associated with a critical nucleus size at which the dynamic energy barrier plays a key role. These dynamic processes of diamond formation provide insight into the establishment of a model for the evolution of ice giant planets.

The authors have no conflicts to disclose.
Conflict of Interest
Bo Chen: Conceptualization (lead); Data curation (lead); Formal analysis (equal); Investigation (lead); Methodology (lead); Validation (equal); Visualization (lead); Writing – original draft (lead); Writing – review & editing (equal). Qiyu Zeng: Conceptualization (equal); Data curation (equal); Formal analysis (supporting); Investigation (supporting); Methodology (equal); Validation (equal); Visualization (equal); Writing – review & editing (equal). Xiaoxiang Yu: Conceptualization (supporting); Formal analysis (equal); Validation (equal); Visualization (equal); Writing – review & editing (supporting). Jiahao Chen: Formal analysis (equal); Validation (supporting); Visualization (supporting); Writing – review & editing (supporting). Shen Zhang: Formal analysis (supporting); Methodology (supporting); Validation (supporting); Writing – review & editing (supporting). Dongdong Kang: Formal analysis (supporting); Funding acquisition (supporting); Validation (supporting); Writing – review & editing (supporting). Jiayu Dai: Conceptualization (equal); Data curation (equal); Funding acquisition (lead); Project administration (lead); Resources (lead); Supervision (lead); Writing – review & editing (lead).
Author Contributions
The data that support the findings of this study are available from the corresponding author upon reasonable request.

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References(66)

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