Synthesis of bulk hexagonal diamond

Liuxiang Yang, Kah Chun Lau, Zhidan Zeng, Dongzhou Zhang, Hu Tang, Bingmin Yan, Guoliang Niu, Huiyang Gou, Yanping Yang, Wenge Yang (), Duan Luo () and Ho-kwang Mao ()
Additional contact information
Liuxiang Yang: Center for High Pressure Science and Technology Advanced Research
Kah Chun Lau: California State University, Northridge
Zhidan Zeng: Center for High Pressure Science and Technology Advanced Research
Dongzhou Zhang: University of Chicago
Hu Tang: Center for High Pressure Science and Technology Advanced Research
Bingmin Yan: Center for High Pressure Science and Technology Advanced Research
Guoliang Niu: Center for High Pressure Science and Technology Advanced Research
Huiyang Gou: Center for High Pressure Science and Technology Advanced Research
Yanping Yang: Center for High Pressure Science and Technology Advanced Research
Wenge Yang: Center for High Pressure Science and Technology Advanced Research
Duan Luo: Chinese Academy of Sciences
Ho-kwang Mao: Center for High Pressure Science and Technology Advanced Research

Nature, 2025, vol. 644, issue 8076, 370-375

Abstract: Abstract Hexagonal diamond (HD), with anticipated physical properties superior than the known cubic diamond, has been pursued relentlessly since its inception 60 years ago1. However, natural and synthetic HD has only been preserved as a highly disordered component in fragile, heterogeneous mixtures of other nanocarbon structures that precludes determination of bulk properties and identification of HD as a bona fide crystalline phase2–4. Here we report the synthesis, recovery and extensive characterization of bulk HD by compressing and heating high-quality graphite single crystals under controlled quasi-hydrostatic conditions. We demonstrate the successful synthesis of 100-µm-sized to mm-sized, highly ordered, bulk HD. We observed direct transformation of graphite ( $$10\bar{1}0$$ 10 1 ¯ 0 ) orientation to HD (0002) and graphite (0002) to HD ( $$10\bar{1}0$$ 10 1 ¯ 0 ). The bulk sample consists of threefold intergrowth of tightly knitted 100-nm-sized crystals, predominantly HD with trace imperfections of cubic diamond. The interlayer bonds in HD are shortened with respect to intralayer bonds to optimize the HD structure. Notably, the hardness of HD is only slightly higher than cubic diamond. We anticipate that purifying the precursor graphite carbon and fine-tuning the high pressure–temperature (P–T) synthesis conditions may lead to higher-quality HDs.

Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41586-025-09343-x Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:644:y:2025:i:8076:d:10.1038_s41586-025-09343-x

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/s41586-025-09343-x

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().