We have detected that you do not have the latest version of Flash player installed.
Please click here to download the Flash plugin

If you do not wish to download the latest version of Flash player please click here to bypass detection.

Chips and Diamonds

Graphene is a one atom thick layer of Carbon atoms bonded into a hexagonal pattern with each carbon atom bound to three others.

Ok , so it's a very fine bit of chicken wire made of carbon with holes about 0.15nm across. So why all the fuss?

Graphene

Well, it does have some rather interesting properties. It is the best conductor of electricity ever discovered. Even better than silver, the previous record holder and much better than boring old copper. It is not a simple metallic conductor though; it is a highly efficient semi conductor, like silicon or germanium, only vastly better. That means, you should be able to make transistors out of it.

Transistors

Transistors are what computer chips are made from. Are we starting to see the possibilities?

It's getting hot in here

Graphene transistors should be able to switch on and off thousands of times quicker than silicon chips. The ability to conduct heat is also crucial in this application. If you look at a modern computer, the CPU (Central Processing Unit) is about the size of your little finger nail but is surrounded by massive lumps of metal and cooling fans designed to stop it overheating. This is one of the limiting factors for the speed of computers. The harder a chip works the hotter it gets and the more difficult it is to remove the heat. Graphene chips should be much easier to cool and therefore be able to work much harder.

Tough chip

Graphene is also incredibly strong. It has breaking strength more than 200 times that of steel. Imagine car bodies as strong as steel but 200 times lighter. Now that would put your miles per gallon up! Think what it might do for the aircraft industry.

That's all very impressive, but what else can we get from it?

Diamond Mine

How about man-made diamonds? Diamonds are another manifestation of carbon. The traditional way to make a diamond is to take some carbon, bury at a depth of about a hundred miles and let extreme temperatures and pressures change it into lumps of hard shiny stuff that cost a packet. At least that used to be the way to do it.

Today a new diamond manufacturing technology has made growing synthetic diamonds cost effective for the very first time. These diamonds are chemically, optically and physically diamond. Diamond is, after all, just an allotrope of carbon. Carbon is carbon, so diamond is diamond. There is no way to tell a man made diamond from a natural one. This has the diamond mining companies rather worried!

How do you manufacture a diamond?

Diamond Production

Basically you need a very large pressure cooker capable of reaching the pressures and temperatures you find deep in the Earth's crust. A set of massive 'anvils' squeeze a pure piece of graphite up to a huge pressure around a tiny diamond 'seed'. This pressure needs to be around 6 billion Pa! This is the sort of pressure you would get at the bottom of an imaginary ocean 600Km deep. These extreme conditions allow the carbon atoms to rearrange themselves from the flat sheet like structure you get in pencil lead to the tetrahedral crystalline structure of diamond. It is not easy thing to achieve. Around 500 different parameters need to be controlled. If you can do all this, and you get it just right, out will pop a brand new diamond.

How big?

Well, we are not going to get diamonds the size of a foot ball. The largest synthetic diamonds are around 10 carats (2g). To put that in perspective, the Koh-I-Noor diamond in the crown jewels is 105.6 carats (21.6 g). So still a way to go then!

Crown Jewels

Big Questions

Carbon can occur in many different forms or allotropes.

Different allotropes can have very different properties.

Some properties of Carbon allotropes may be extremely useful.