Author Topic: dislocation analysis  (Read 102 times)

bahmanpbamp

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dislocation analysis
« on: September 20, 2018, 10:26:56 AM »
Dear experts,

I am going to apply dislocation analysis for a 2D fcc model. However, OVITO tells that it does not support 2D. So, can I make a trick and change the z positions of all atoms from 0 to 1?

any comment is highly appreciated.

Yours Sincerely,
Bahman

Alexander Stukowski

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Re: dislocation analysis
« Reply #1 on: September 20, 2018, 10:43:35 AM »
Dear Bahman,

I'm not sure if I understand: What exactly is a "2D fcc model"? Face-centered cubic crystal lattices are by definition three-dimensional.

-Alex

bahmanpbamp

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Re: dislocation analysis
« Reply #2 on: September 20, 2018, 11:41:44 AM »
Dear Alex,

Thank you for your response. yes, my 2D model is made from (111) plane of fcc structure.

Regards,
Bahman

Alexander Stukowski

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Re: dislocation analysis
« Reply #3 on: September 20, 2018, 11:52:10 AM »
I see. So you actually would like to identify dislocations in a hexagonal lattice.

The DXA function in OVITO does not support any 2D crystals, i.e. sheet-like materials like graphene and your hexagonal lattice. The algorithm was only implemented for three-dimensional crystals such as fcc and bcc, where dislocations are 1-dimensional (line-like) defects.

Identifying dislocation in 2d crystals requires a different method, but happens to be much easier, because here dislocations are 0-dimenesional defects. Here is a paper describing a simple algorithm for finding dislocations in 2d lattices:

https://www.sciencedirect.com/science/article/pii/S0022509614001331

I cannot give you a ready-to-use code for this, but it should be relatively easy to implement this algorithm in a Python script. Maybe this is something you can do yourself.