Thickness of Graphene: Theory & Measurement

[kevinisfrom]

Hello,

I was just wondering what the theoretical thickness of single layer graphene is?

Thanks in advance for any feedback.

 

[NeedBranes]

A single layer of graphene would be one atom thick, carbon.

 

[kevinisfrom]

Do you know the answer in Angstroms?

 

[NeedBranes]

1 Angstrom is .0000000001 meters, carbon is 1.54 Angstroms

 

[kevinisfrom]

a carbon atom is not the same thing as graphene. do you know the thickness of graphene in Angstroms?

 

[Greg Bernhardt]

a carbon atom is not the same thing as graphene. do you know the thickness of graphene in Angstroms?

This paper might give some clues
http://arxiv.org/pdf/0812.0690.pdf

 

[NeedBranes]

A carbon atom is not the same thing as graphene but a "sheet" of carbon atoms is. 1 layer thick sheet of graphene is one atom thick. Wrap it in a cylinder, you have a carbon nanotube, put it in a ball you have a buckyball, stack one sheet of graphene on one sheet of graphene you have graphite. I could be wrong, I am no expert.

 

[kevinisfrom]

Hi Greg, thank you for the reply. Your link is an experimental paper. I was hoping for the theoretical value of graphene's thickness, and also the interlayer spacing between graphene sheets in graphite.

 

[kevinisfrom]

There are sp2 bonds between C atoms. It's different from an isolated atom.

 

[Kholdstare]

Hello,

I was just wondering what the theoretical thickness of single layer graphene is?

Thanks in advance for any feedback.

Thickness is a confusing quantity. You should define how you relate thickness of something with actual length between two particular points in that something.

There are sp2 bonds between C atoms. It's different from an isolated atom.

Hi Greg, thank you for the reply. Your link is an experimental paper. I was hoping for the theoretical value of graphene's thickness, and also the interlayer spacing between graphene sheets in graphite.

Again this depends on what is the definition of thickness.

AFM depends on Coulombic repulsion to measure thickness. Its hard to tell exactly where is the surface of the layer. Or how do you define the surface of the layer.

A single layer of graphene would be one atom thick, carbon.

True in a sense. The "thickness" of graphene is one carbon atom "thick".

 

[kevinisfrom]

Thanks for the replys. I know there is a widely accepted theoretical value for the thickness, considering all the atom-atom interactions and whatnot. It's just a number. I understand there is a lot to consider when doing AFM scans, but there should be a simple answer to this question theoretically. I knew it once, but have since forgotten.

 

[Kholdstare]

Thanks for the replys. I know there is a widely accepted theoretical value for the thickness, considering all the atom-atom interactions and whatnot. It's just a number. I understand there is a lot to consider when doing AFM scans, but there should be a simple answer to this question theoretically. I knew it once, but have since forgotten.

I can give a very naive answer. Try C-C bond length/2 as the radius of the atom. Then the thickness becomes just C-C bond length. Of course it complicates with the nature of bonds or other elements etc.

Also, you can use non-bonding p-orbital electrons of sp2 for rough thickness calculation. Just take the mean radius of their orbital. But then again it will register different in AFM as after bonding with AFM tip, the electronic configuration might change.