Hi everyone,
I have done some preliminary calculations on a vdWs 2D monolayer by substituting atoms at one of its atomic sites in the unit cell itself. I find negative formation energy and stable mechanical properties.
However, when I look into the literature, there are only studies on substitutional doping using a supercell. My approach is different in the way that I am suggesting the possibility of new 2D compounds using just the unit cell.
Is this type of study acceptable to the scientific community? Are there articles in literature that have undertaken such studies using DFT or even experimentally?
Best,
Eesha
I did find one recent paper: 'Tunable electronic properties of porous graphitic carbon nitride (C6N7 ) monolayer by atomic doping and embedding: A first-principle study', where they do not build a SC.
One additional complication here is not necessarily whether the compound you describe is more stable than the elements it is formed from, but also whether it is the most stable isomorph.
It is entirely possible that the system you have discovered is metastable, or even unstable compared to a different stoichiometric combination of the elements or structure (for example, diamond is meta-stable whereas graphite is more stable - whereas if you started with bulk silicon and performed a logical substitution for carbon you would only find the diamond structure).
While your initial results are promising, to convince an experimentalist that it is worth their time trying to synthesize your material, they would probably want to see more data covering a larger proportion of the phase space for the combination of these materials. I would also expect this type of more in-depth study would also be expected by referees if you wished to publish your work as a discovery of a new material.
This is frequently done using techniques such as genetic algorithms and random structure searching, for example:
Phys. Rev. Materials 5, 123801 (2021) - Navigating the Ti-C-O and Al-C-O ternary systems through theory-driven discovery (aps.org)
Hope that helps,
Robert
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