Suggestion for crystalline material definition #8
Conversation
jamesrhester
requested review from
CasperWA,
sauliusg,
emanueleghedini and
jesper-friis
CasperWA
requested review from
rartino
and removed request for
emanueleghedini
| ### Preferred label | ||
| "crystalline material" | ||
| ### Alternate labels | ||
| "crystal", "three-dimensional crystal", "periodic crystal", "powder" |
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I am little concerned about "powder" as alternative label, both because we discuss powder as an own concept but also because a powder does not need to be crystalline in my vocabulary (I would e.g. call fine crushed glass for a powder).
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How about "crystalline powder" instead?
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Following today's discussion, I wonder if it wouldn't be better to broaden this concept slightly to include any material for which some component of it is modelled using a crystal structure model, instead of requiring that all components are crystalline? In many cases real-world powders, e.g. from mineral prospecting, contain some amorphous component which needs to be modelled, so it would be good if data files from such materials are not excluded simply because some part of them is not crystalline. Also, Casper's zeolites would be excluded by this definition when loaded with disordered water, but not when unloaded, which seems a bit silly. |
Good point. At the same time I guess that we don't want to call wood a crystalline material, even we have in the TEM observed some nanoscale crystallites in wood fibers. Would it make sense to split it up into more concepts? One, which is well-described by a crystalline model and one for which at least some of its component is modelled using a crystal structure model? The latter class would include your powder, Casper's zeolites and wood. To distinguish wood from the two former, one may do a diffraction experiment. Unless you are doing a nanobeam diffraction in the TEM, I guess you would not see a diffraction pattern from wood, while the powder and zeolites would show a diffraction pattern. |
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OK, so we would have a "purely crystalline material" and a "crystal-containing material". The "crystal-containing material" I think is an important class as it will capture composites like (it turns out) wood and teeth and synthetic composites with important materials engineering properties, as well as zeolites and powders with amorphous phases. I'm happy with this suggestion, anybody else have any thoughts? |
Recent discussion has revealed that the semiotic process would allow us to link data, crystallographic models and real objects using semiotic processes. In this case, there is no need to immediately describe every elaboration of the single crystal model, instead we can build up various classes of materials in the Physicalistic perspective with no need to consider measurements or models.
The previous commit accidentally switched this concept to being for an ideal crystal. The present commit fixes that, and rewrites it to be more in line with EMMO thinking.
Please review and improve.