QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: marmotte on September 15, 2012, 22:52
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Dear QW team,
I'm learning QW since our purchase. I'd like to access to tutorials on how to build interfaces like Fe/MgO/Fe ( we have them already throughout a script and special builder). In fact, I'd like to model MTJ systems such as FeCoB/STO/FeCoB for example. could you show me a general tutorials that I can apply for special cases ?
Thanks in advance :D
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check out:
http://www.quantumwise.com/documents/tutorials/latest/Fe-MgO-Fe/index.html/
We are working on non-collinear spin and there will be a new tutorial on these aspects.
Let us know if there are aspects in the other tutorial you find missing, then we may add them in the new one.
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For a more general example on how to build an interface, see http://quantumwise.com/publications/tutorials/builder/170-building-a-si-si3n4-interface. But it would perhaps be a good idea to use a similar system that you mentioned as an example of a perhaps slightly simpler interface.
What do you think of the attached system, compared to http://arxiv.org/abs/cond-mat/0511663 (Chapter 6)
If you think it makes sense, I can show how I built it!
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Dear Anders,
Thank you very much !
Yes, I will appreciate of you can help me to build CoFeB/STO/CoFeB.
Best regards,
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Ok, we can look into that. But "CoFeB" is not a trivial crystal structure, it needs to be specified better what is meant precisely.
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It look like an alloy FeCo doped by B in interstitial position. Please see APPLIED PHYSICS LETTERS 89, 142507 2006, where it is reported
" we use the supercell which consists of 11 layers of CoFe and 5 layers of MgO. The in-plane lattice constant is constrained to be that of bulk CoFe, a
=2.84 Å. Due to the lattice mismatch of 5.2%, the MgO is compressed in plane and this induces a volume conserving
tetragonal distortion of the barrier layer perpendicular to the plane of the fil m of about 4%. For the clean interface no B
an equilibrium Fe–O distance of 2.23 Å is found for the Fe terminated interface, while for the Co terminated interface
the Co–O distance is 2.16 Å. Ripples in the interfacial MgO i.e., the displacement of O atoms relative to the Mg atoms in the same atomic layer are less than 0.06 Å for both terminations"