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Diamond nanocrystals formed by direct implantation of fused silica with carbon

Version 2 2024-06-17, 23:08
Version 1 2017-03-12, 11:12
journal contribution
posted on 2024-06-17, 23:08 authored by JO Orwa, S Prawer, DN Jamieson, JL Peng, JC McCallum, KW Nugent, YJ Li, LA Bursill, SP Withrow
We report synthesis of diamond nanocrystals directly from carbon atoms embedded into fused silica by ion implantation followed by thermal annealing. The production of the diamond nanocrystals and other carbon phases is investigated as a function of ion dose, annealing time, and annealing environment. We observe that the diamond nanocrystals are formed only when the samples are annealed in forming gas (4% H in Ar). Transmission electron microscopy studies show that the nanocrystals range in size from 5 to 40 nm, depending on dose, and are embedded at a depth of only 140 nm below the implanted surface, whereas the original implantation depth was 1450 nm. The bonding in these nanocrystals depends strongly on cluster size, with the smaller clusters predominantly aggregating into cubic diamond structure. The larger clusters, on the other hand, consist of other forms of carbon such as i-carbon and n -diamond and tend to be more defective. This leads to a model for the formation of these clusters which is based on the size dependent stability of the hydrogen-terminated diamond phase compared to other forms of carbon. Additional studies using visible and ultraviolet Raman Spectroscopy, optical absorption, and electron energy loss spectroscopy reveal that most samples contain a mixture of sp2 and sp3 hybridized carbon phases.

History

Journal

Journal of applied physics

Volume

90

Pagination

3007-3018

Location

Melville, N.Y.

ISSN

0021-8979

Language

eng

Publication classification

C Journal article, C1.1 Refereed article in a scholarly journal

Copyright notice

2001, American Institute of Physics

Issue

6

Publisher

American Institute of Physics

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