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During the CVD process, Copper and Nickel which are both Face Centered Cubic crystalline structures are used as substrates for shaping hexagonal atomic structures such as graphene and hexagonal Boron-Nitride. Why is it that these form hexagonal atomic structures when they themselves aren't hexagonal?

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    $\begingroup$ But they are hexagonal, if you look at them sideways. $\endgroup$ Dec 29, 2022 at 14:54
  • $\begingroup$ Sorry I dont quite grasp what you mean. Do you have a visual representation? $\endgroup$
    – Andi Iacob
    Dec 29, 2022 at 15:01
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    $\begingroup$ Fcc and hcp structures are similar stacking (fcc you need to look along the 111 body diagonal - a classic issue with the cubic conventional cell). $\endgroup$
    – Jon Custer
    Dec 29, 2022 at 15:14
  • $\begingroup$ @AndiIacob for that check my answer to Silver (111) surface structure, and is bulk structure body-center or face-center cubic? Basically the "centered" lattices (fcc, bcc in 3D, centered rectangular in 2D) are contrived to be human friendly; the actual primitive unit cells are much smaller and oblique, and the 3D ones result in horizontal hexagonal planes when the "cubes" are stood up on their corners. $\endgroup$
    – uhoh
    Dec 30, 2022 at 5:03
  • $\begingroup$ @uhoh so this means there are no modifications needed to the substrate correct? Om effect, any FCC could theoretically be used to make hexagonal shapes? And BCC as well? $\endgroup$
    – Andi Iacob
    Jan 5, 2023 at 9:54

1 Answer 1

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[Ivan Neretin] But they are hexagonal, if you look at them sideways. – 

[OP] Sorry I dont quite grasp what you mean. Do you have a visual representation?

Here is the visual.

enter image description here

[Jon Custer] Fcc and hcp structures are similar stacking (fcc you need to look along the 111 body diagonal - a classic issue with the cubic conventional cell).

Yes, both may be constructed by stacking hexagonal layers, either in an ABABA.. (hexagonal close packing hcp) or an ABCABCA.. (face-centered cubic fcc) fashion.

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  • $\begingroup$ Nice visual there! $\endgroup$
    – Jon Custer
    Dec 29, 2022 at 23:53
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    $\begingroup$ I've linked to your answer here +1 $\endgroup$
    – uhoh
    Dec 30, 2022 at 5:06

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