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by tokenadult 5054 days ago
Let's see what the actual journal article says.

http://www.sciencemag.org/content/337/6096/825.abstract?sid=...

Long-Range Ordered Carbon Clusters: A Crystalline Material with Amorphous Building Blocks Lin Wang, Bingbing Liu, Hui Li, Wenge Yang, Yang Ding, Stanislav V. Sinogeikin, Yue Meng, Zhenxian Liu, Xiao Cheng Zeng, and Wendy L. Mao Science 17 August 2012: 337 (6096), 825-828. [DOI:10.1126/science.1220522]

The Science editors also solicited a commentary

http://www.sciencemag.org/content/337/6096/812.summary

on the article.

AFTER EDIT:

As I read through the full-text article, it seems that the kind of nanoscale observations being reported in the article might be consistent with the "new" material simply being local, small-scale diamonds (the substrate material was carbon molecules, after all, before they were subjected to high pressure), being "as incompressible as diamond," as reported, for the unremarkable reason that it is diamond. But I will defer to someone who is more knowledgeable than I in materials science to see what other interpretation of the published article might make more sense.

3 comments

Materials Scientist here.

There are no small-scale diamonds present in the material. On the small scale, the material is a carbon glass (an unordered, or amorphous solid), distinct from diamond, which is an ordered crystal. Typically, high density glasses are stronger than crystals made from the same elements, so the strength of the material isn't particularly surprising, rather it's the processing of the new material that is novel.

It's also worth noting that this isn't even the first carbon-based material stronger than diamond. Lonsdaleite is a closely related structure that is significantly stronger. It is much less common, however, naturally occurring only in meteorites.

Any idea as to which one is actually harder, the new material, or Lonsdaleite? I see from this journal that Lonsdaleite has 58% higher indentation strength than diamond: http://prl.aps.org/abstract/PRL/v102/i5/e055503 but I couldn't find figures for the new material.
Here is the full pdf: https://filetea.me/t1se48ed
Thanks for posting that!