incommensurate interface

[semran]

Dear QuantumWise users and developers,

I have been trying to figure out how to construct incommensurate interface of two different slabs for a while.

Actually, I have tried to use the tutorial dealing with the commensurate graphene interfaces. As I understood from the literature, incommensurate interface means that symetry points of two material do not match.
So if I construct the interface using the interface builder then set matching parameters such that rotation between cells is big enough not to match symetry points (high strain as well), then it will end up with incommensurate interface...
Am I right?
Could you shed light on this? I would appreciate any help.

best,

ipek

[Ulrik G. Vej-Hansen]

The problem with incommensurate systems is that it is, in general, very difficult to have both materials in their equilibrium structure, while also having periodic boundary conditions. What you describe sounds reasonable, but if you could please provide some more information on exactly what you would like to do, we can be of more help to you.

[semran]

Dear Dr.Ulrik,


Thank you for your reply. Actually, I have been tryingto construct an incommensurate interface of Graphite and Sb(111).
I am changing matching parameters from "set matching parameters"menu.
İf rotation angle is big enough and strain is in a reasonable range, then can we say that all interfaces satisfying these conditions can be regarded as incommensurate interface.?
This also means that if strain is too low, the interface should be commensurate one..

I am attaching my interface constructed by interface menu of VNL. Can I say that my interface is insommensurate one?

Thank you very much.

Regards,,

ipek

[Ulrik G. Vej-Hansen]

Dear Ipek

Your configuration certainly satisfies the periodic boundary conditions, so yes, I would say that you can do reasonable calculations with this system. In my experience, incommensurate has mostly been used as a negative, describing an interface where the two surfaces do not match under equilibrium conditions. However, if you need to verify that it satisfies a specific set of conditions, please provide a reference.

[semran]

Dear Dr.Ulrik,

I really appreciate for your help.  My reference article is  DOI: 10.1103/PhysRevB.84.085449. This article constructs an incommensurate Graphite/Sb interface.
And they claim that in that interface the friction is too low.
I am trying to reproduce their results.
But I can not achive to produce their interface they have given in that paper. Am I missing something while constructing the interface?

Thank you for your valuable contributions..

regards,

ipek

[Ulrik G. Vej-Hansen]

As far as I can see, there is quite a big difference between the two friction values, so how far off is your value? They specifically state that there are several ways to construct the incommensurate cell, so maybe yours is simply one of the others, resulting in a some deviation from their stated friction value?

Which crystal structure have you used for Sb? Have you verified that it is the same as used in the paper?

[semran]

Dear Dr. Ulrik,


I definetly do what you suggest. But it seems my way to construct the incommensurate interface by changing settings in "Set Matching parameters" in interface menu is reasonable.

Thanks a lot. İt is now more clear for me..

Regards,
ipek