Neo-polymorph: Difference between revisions
→External links: added note on mineralienatlas.de as inspiration source for neo-polymorphs |
|||
| (25 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
{{wikitodo|There was a significant mixup with '''neo-isotypes''' here. Do some more cleanup & checks if transition succeeded.}} | |||
{{site specific term}} | {{site specific term}} | ||
This includes patterns where specifically ordered states are thermodynamically not more attractive than disordered (or in other undesired form ordered) states but where a (sufficiently) high activation energy lies between the ordered and unordered states. | A '''neo-polymorphic compound''' (or neo-isomorphic compound) is a highly (meta)stable non equilibrium polymorph <br> | ||
of a material with a certain fixed stoichiometry that is exclusively accessible through [[mechanosynthesis]]. <br> | |||
If just one element is involved the term '''[[neo-allotrope]]''' can be applied too/instead. | |||
This includes patterns where specifically ordered states are thermodynamically not more attractive <br> | |||
than disordered (or in other undesired form ordered) states but <br> | |||
where a (sufficiently) high activation energy lies between the ordered and unordered states <br> | |||
making the via conventional means inacessible states highly kinetically metastable. <br> | |||
The patterns can be: | The patterns can be: | ||
* different | * different stacking geometry, specific example: <br>A crossover between Diamond (cubic stacking) and lonsdaleite (hexagonal stacking). <br>(When pointing up a tetrapod of carbon bonds there are two ways one can orient the up facing three bonds in a six direction hexagon). | ||
* changes between different crystal structures of the same composition (adn stoichometry) so long nigh seamless covalent transitions are possible | |||
Excluded here: | |||
* changes of atom types and stoichometry falls under [[neo-isotypes]] instead: <br>specific example: A crossover gemstone between Rutile (polymorph of TiO<sub>2</sub>) and stishovite (polymorph of SiO<sub>2</sub>). <br>The pattern making elements are Ti & Si. Oxygen atoms stay at their places. | |||
Stacking order patterns: | |||
* ABABBABBBBAABABAABAA – unwanted unordered state – may be the only one that is thermodynamically accessible | * ABABBABBBBAABABAABAA – unwanted unordered state – may be the only one that is thermodynamically accessible | ||
* ABABABABABABABABABAB – unwanted ordered state – may be the only one that is thermodynamically accessible | * ABABABABABABABABABAB – unwanted ordered state – may be the only one that is thermodynamically accessible | ||
* | * ABBAABBAABBAABBAABB – '''neo-polymorph''' – wanted peculiarly ordered state – not thermodynamically accessible - but accessible via [[mechanosynthesis]] | ||
Note: in the case of SiC ([[moissanite]]) there is the constraint of no two same letters following adjacently. Above examples for simplicity. | |||
Also '''[[neo-polymorphs]] and [[neo-isotypes]] can intermix here to [[neo gemstones like compounds]]''' or '''neo-gems''' for short. <br> | |||
All sorts of II-IV semiconductor compounds have fitting structure stacking order variations in {111} directions. <br> | |||
So structural stacking order can be augmented with material type stacking order. <br> | |||
Material stacking order not being constrained to the by {111} directions but by lattice strain. <br> | |||
Note: '''Thermodynamic accessibility''' refers to all the crude processes available today ( | Note: '''Thermodynamic accessibility''' refers to all the crude processes available today (2025) <br> | ||
that only allow to handle matter in statistical quantities: <br< | |||
melting, mixing, cooling, pressurizing, irradiating, ([[cook mix and stir thermodynamic synthesis]]) ... <br> | |||
This explicitly excludes advanced [[mechanosynthesis]]. | |||
== Examples == | == Examples == | ||
| Line 22: | Line 37: | ||
See: [[pseudo phase diagrams]] for more details on this. | See: [[pseudo phase diagrams]] for more details on this. | ||
* [[Dialondeite]] cubic to hexagonal series | |||
* [[Moissanite]] cubic to hexagonal series | |||
* genrally: cubic zincblende structure to hexagonal wurzite structure series (for all applicable compounds respectively, mostly III-V semiconductors) | |||
---- | |||
Other patternd back and forth transitions between small chunks of highly compatible crystal structures: | |||
* [[withe sapphire]] to [[deltalumide]] (unclear if transitionable) | |||
* [[silicon nitride]] trigonal alpha to hexagonal beta & (unclear) to cubic gamma | |||
* SiO<sub>2</sub> low pressure modification transitions - see page: [[Quartz]] | |||
* … {{wikitodo|Find more examples to put here}} | |||
* | |||
[[ | |||
== Related == | == Related == | ||
* [[ | * [[Neo-gems]] | ||
* '''[[Neo-isotypes]]''' | |||
---- | |||
* [[Classifications for gemstone like compounds]] | |||
---- | |||
* '''[[Pseudo phase diagram]]''' - mapping out neo-polymorphs | |||
* [[Simple crystal structures of especial interest]] - browse there as a starting point | * [[Simple crystal structures of especial interest]] - browse there as a starting point | ||
----- | ----- | ||
* [[ | * [[Diamondoid compound]] | ||
* [[ | * [[Binary diamondoid compound]] | ||
---- | |||
* [[Kaehler bracket]]s | |||
---- | |||
'''Examples:''' | |||
* [[Dialondeite]] | |||
== External links == | == External links == | ||
| Line 77: | Line 78: | ||
---- | ---- | ||
* [https://www.mineralienatlas.de/ www.mineralienatlas.de] <br>lists minerals with equal or similar structures for any given mineral <br> so thhis can serve as a possible starting point to find potential neo-polymorphs | * [https://www.mineralienatlas.de/ www.mineralienatlas.de] <br>lists minerals with equal or similar structures for any given mineral <br> so thhis can serve as a possible starting point to find potential neo-polymorphs | ||
[[Category:Far term target]] | |||
Latest revision as of 19:10, 29 March 2026
(wiki-TODO: There was a significant mixup with neo-isotypes here. Do some more cleanup & checks if transition succeeded.)
A neo-polymorphic compound (or neo-isomorphic compound) is a highly (meta)stable non equilibrium polymorph
of a material with a certain fixed stoichiometry that is exclusively accessible through mechanosynthesis.
If just one element is involved the term neo-allotrope can be applied too/instead.
This includes patterns where specifically ordered states are thermodynamically not more attractive
than disordered (or in other undesired form ordered) states but
where a (sufficiently) high activation energy lies between the ordered and unordered states
making the via conventional means inacessible states highly kinetically metastable.
The patterns can be:
- different stacking geometry, specific example:
A crossover between Diamond (cubic stacking) and lonsdaleite (hexagonal stacking).
(When pointing up a tetrapod of carbon bonds there are two ways one can orient the up facing three bonds in a six direction hexagon). - changes between different crystal structures of the same composition (adn stoichometry) so long nigh seamless covalent transitions are possible
Excluded here:
- changes of atom types and stoichometry falls under neo-isotypes instead:
specific example: A crossover gemstone between Rutile (polymorph of TiO2) and stishovite (polymorph of SiO2).
The pattern making elements are Ti & Si. Oxygen atoms stay at their places.
Stacking order patterns:
- ABABBABBBBAABABAABAA – unwanted unordered state – may be the only one that is thermodynamically accessible
- ABABABABABABABABABAB – unwanted ordered state – may be the only one that is thermodynamically accessible
- ABBAABBAABBAABBAABB – neo-polymorph – wanted peculiarly ordered state – not thermodynamically accessible - but accessible via mechanosynthesis
Note: in the case of SiC (moissanite) there is the constraint of no two same letters following adjacently. Above examples for simplicity.
Also neo-polymorphs and neo-isotypes can intermix here to neo gemstones like compounds or neo-gems for short.
All sorts of II-IV semiconductor compounds have fitting structure stacking order variations in {111} directions.
So structural stacking order can be augmented with material type stacking order.
Material stacking order not being constrained to the by {111} directions but by lattice strain.
Note: Thermodynamic accessibility refers to all the crude processes available today (2025)
that only allow to handle matter in statistical quantities: <br<
melting, mixing, cooling, pressurizing, irradiating, (cook mix and stir thermodynamic synthesis) ...
This explicitly excludes advanced mechanosynthesis.
Examples
See: pseudo phase diagrams for more details on this.
- Dialondeite cubic to hexagonal series
- Moissanite cubic to hexagonal series
- genrally: cubic zincblende structure to hexagonal wurzite structure series (for all applicable compounds respectively, mostly III-V semiconductors)
Other patternd back and forth transitions between small chunks of highly compatible crystal structures:
- withe sapphire to deltalumide (unclear if transitionable)
- silicon nitride trigonal alpha to hexagonal beta & (unclear) to cubic gamma
- SiO2 low pressure modification transitions - see page: Quartz
- … (wiki-TODO: Find more examples to put here)
Related
- Pseudo phase diagram - mapping out neo-polymorphs
- Simple crystal structures of especial interest - browse there as a starting point
Examples:
External links
Wikipedia pages:
- Polymorphism (materials science)
- Polymorphs of silicon carbide
- isomer, stereoisomer, conformational isomer
- Superstructure (condensed matter)
- Isomorphism_(crystallography)
- Isotype: (de) Translated citation: "Minerals of the same structural type are called isotypes. They crystallize in the same class of crystals and form similar crystal forms. "
- Isotype: (wikipedia de) Isotyp
- www.mineralienatlas.de
lists minerals with equal or similar structures for any given mineral
so thhis can serve as a possible starting point to find potential neo-polymorphs