October 9th: Precious


If someone gives you a diamond proclaiming it symbolises how their love will last forever, be ready to reply: “Liar!”

The precious diamonds are a material made exclusively of carbon. There is another material with the same exact composition: graphite (i.e. the lead in pencils). The only difference is their atomic and crystal structure. While carbon atoms in diamonds are arranged in a tetrahedral structure, making diamonds the hardest natural material on earth, the atoms in graphite are organised in layers of regular hexagons easy to flake apart. Because graphite has more entropy than diamond –and everything in the Universe moves toward greater entropy– given enough time* diamonds will turn into graphite.

Now, I don’t want to say that love is ephemeral and would inevitably turn into something easy to flake and break apart. And even if I did, that is not necessary a bad thing. Andre Geim discovered a new material by breaking apart a single layer of graphite: graphene**. And he did it by using sticky tape on graphite and tearing it off.

Graphene is a fantastic material: being only one atom thick, it is a purely 2D crystal. As a consequence, electrons in graphene behave in weird ways – they “lose” their mass and move at very high speed feeling extremely low resistance in the material. The applications for graphene extend to many fields, from electronics to biosensors.

At the end of the day, even love might be better represented by graphene rather than diamonds: both behave in weird ways that we still have to fully understand and offer every day something new to discover.

Bonus: In the picture, Andre Geim is floating in space “swimming” frog style. Any idea why? 

* Enough time is 10-100s billions of years (or high temperature and few minutes), so, to be fair, diamonds are still pretty much forever and if someone gives them to you, maybe they really care and you should be happy about it.

** Graphene was already theorised and had even been measured before Geim and Novoselov produced it in 2004. However, before their discovery, it was only produced in small quantity and always needed additional materials as substrates. This prevented extensive study on graphene.

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