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General Questions and Answers / Re: Building 6H-SiC Question
« on: September 11, 2015, 14:50 »
BTW. We'll soon have a brand new tutorial on vapor deposition simulations on the SiC(0001) surface..
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I've been reading,
Ogasawara N, Norimatsu W, Irle S, Kusunoki M. Growth mechanisms and selectivity for graphene or carbon nanotube formation on SiC (0001¯): A density-functional tight-binding molecular dynamics study. Chemical Physics Letters [serial online]. March 18, 2014;595-596:266-271. Available from: ScienceDirect, Ipswich, MA. Accessed September 11, 2015.
They use 5x5x.5 unit cells, I wonder if that is a coincidence?
In the diagram the structure looks similar to " 6H SiC Example.png " in my original post. I'm guessing the structure in Jakse was not really meant to represent the physical appearance of the material from one face, but perhaps just a 2-d representation of the stacking sequence?
If you import the .cif file, attached in my previous post, into the Builder (via Add > From Files), you will see that it has 12 atoms, although the cif file has only 6 coordinates. The remaining coordinates are deduced from the symmetry.
I'm confused, doesn't 6H-SiC have 12 atoms in a unit cell? There's only 6 in the coordinates you gave for 6H.
Also, different sources seem to get different structures for the unit cell, is there more than one?
My knowledge in solid state physics is limited. I'm trying to build 6H-SiC to run tests on the surfaces. I'm not sure if I'm doing this correctly. I start with the Hexagonal SiC in the data base, it consists of 4 atoms. I repeat it and then move atoms around to get the structure of the 6H-SiC unit cell (12 atoms) by going off schematics I've found from various sources. Then I repeat the 6H-SiC structure 5X5X1. I attached images of two of my stash items with the unit cell and the 5X5X1, I also attached two images I looked off of to help me.
Basically my question is...is this right?