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Title: Self‐Limiting Sub‐5 nm Nanodiamonds by Geochemistry‐Inspired Synthesis
Abstract

Controlling diamond structures with nanometer precision is fundamentally challenging owing to their extreme and far‐from‐equilibrium synthetic conditions. State‐of‐the‐art techniques, including detonation, chemical vapor deposition, mechanical grinding, and high‐pressure‐high‐temperature synthesis, yield nanodiamond particles with a broad distribution of sizes. Despite many efforts, the direct synthesis of nanodiamonds with precisely controlled diameters remains elusive. Here the geochemistry‐inspired synthesis of sub‐5 nm nanodiamonds with sub‐nanometer size deviation is described. High‐pressure‐high‐temperature treatment of uniform iron carbide nanoparticles embedded in iron oxide matrices yields nanodiamonds with tunable diameters down to 2.13 and 0.22 nm standard deviation. A self‐limiting, redox‐driven, and diffusion‐controlled solid‐state reaction mechanism is proposed and supported by in situ X‐ray diffraction, ex situ characterizations, and computational modeling. This work provides a unique mechanism for the precise control of nanostructured diamonds under extreme conditions and paves the road for the full realization of their potential in emerging technologies.

 
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NSF-PAR ID:
10419135
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Small
ISSN:
1613-6810
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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