Difference between revisions of "Neo-polymorph"
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| − | + | A '''neo-polymorphic compound''' (or neo-isomorphic compound) is a highly stable non equilibrium polymorph of a material with a certain fixed stoichiometry that is exclusively accessible through [[mechanosynthesis]]. | |
| − | A '''neo-polymorphic compound''' (or neo-isomorphic compound) is | + | |
| + | 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. | ||
| + | |||
| + | The patterns can be: | ||
| + | * different atom types (elements) ... specific example: A crossover gemstone between Rutile (polymorph of TiO<sub>2</sub>) and stishovite (polymorph of SiO<sub>2</sub>). The pattern making elements are Ti & Si. Oxygen atoms stay at their places. | ||
| + | * different stacking geometry or ... 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). | ||
| + | * ... | ||
| + | |||
| + | 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 | ||
| + | * AABBAABBAABBAABBAABB – '''neo-polymorph''' – wanted peculiarly ordered state – not thermodynamically accessible - but accessible via [[mechanosynthesis]] | ||
| + | |||
| + | Of course arbitrary many elements/layertypes/... are allowed. A,B,C,D,... | ||
| + | |||
| + | Note: '''Thermodynamic accessibility''' refers to all the crude processes available today (2020) that only allow to handle matter in statistical quantities: melting, mixing, cooling, pressurizing, irradiating, ... This explicitly excludes advanced [[mechanosynthesis]]. | ||
| + | |||
| + | == Examples == | ||
| + | |||
| + | See: [[pseudo phase diagrams]] for more details on this. | ||
| + | |||
| + | '''The rutile stishovite (TiO<sub>2</sub> to strong SiO<sub>2</sub>) neopolymorphic transition:''' <br> | ||
| + | The common mineral [[rutile]] and the rare mineral [[stishovite]] (made out of the two most common elements in earth crust) share the same crystal structure. The rutile structure. | ||
| + | Albeit rutile not drawing silicon into its structure naturally (meaning it's thermodynamically unfavourable) | ||
| + | (as can be seen with rutile occuring embedded in quartz https://commons.wikimedia.org/wiki/File:Rutile@quartz.jpg) | ||
| + | a forced substitution (at least to some degree) may very well be possible via [[mechanosynthesis|mechanosyntheic]] means | ||
| + | and the resulting product [[base material]] may very well be highly (meta) stable at room temperature. | ||
| + | |||
| + | '''The quartz to "carbexplosoquartz" (SiO<sub>2</sub> to solid CO<sub>2</sub>) neopolymorphic transition''' <br> | ||
| + | Obviously CO<sub>2</sub> very much likes to be a gas (small atomic radii => sp orbitals sticking far out => orbitals hybridize and form double bonds) | ||
| + | so if pure CO is even mechanosynthsizable it would be a very delicate and thus dangerous high explosive. A little bit of substitution of Si with C may be safely forcable via mechanosynthetic means though, despite that substitution is not naturally happening due to unvafourable thermodynamics. Maybe even as much as 50% of the silicon could be substituted with carbon without getting to something unstable and useless? Who knows. | ||
| + | |||
| + | '''The SiO<sub>2</sub> to GeO<sub>2</sub> and SnO<sub>2</sub> neopolymorphic transition''' <br> | ||
| + | Si has a bit more dissimilarity to the element above (C) than the elements below (Ge,Sn) with the exception of (Pb). | ||
| + | Like less relative difference in diameter, less difference in their dislike to form double bonds, less difference in their metallicity, ... . | ||
| + | So these elements may be substitutable in higher quantities. Though Ge and Sn are to rare to be of use as large volume structural base material. | ||
| + | Also Ge and Sn form rutile structure (argutite and cassiereite respectively), so they may instead be able to | ||
| + | tie into the aforementioned rutile stishovite neopolymorphic transition. | ||
| + | Lead (Pb) may very well already be way too different to Si to even be force substitutable making the resulting structures unstable at room temperature or even below. | ||
| + | Lead and tin are (and where) used in the floating glass production process because they don't like to mix too much (on their own volition). | ||
| + | Still a lot of unwettability and immiscibility may be possible to overcome via mechanosynthetic forcing. | ||
| + | Also there is lead glass ({{TODO| find out how lead integrates in glass in the case of lead glass}}) | ||
| + | |||
| + | * '''The Si<sub>3</sub>N<sub>4</sub> to beta carbon nitride C<sub>3</sub>N<sub>4</sub> neopolymorphic transition''' <br> | ||
| + | Both are high performance materials but [[beta carbon nitride]] is highly exotic even in its pure form today (2020). | ||
| + | [[Beta carbon nitride]] may be of especial interest since when drawing solid building material form thin air alone | ||
| + | The concentration of CO<sub>2</sub> is the limiting factor and given more than halve of C<sub>3</sub>N<sub>4</sub> is nitrogen | ||
| + | and thus material may be drawable more than double the speed. | ||
| + | |||
| + | * '''The BN to AlN neopolymorphic transition''' <br> | ||
| + | Pure AlN hydrolyzes with water, so when going far with the forced substitutuion the parts must be perfectly sealed against humidity. | ||
| + | |||
| + | * '''The tistarite to leukosapphire to diboron trioxide (Ti<sub>2</sub>O<sub>3</sub> to Al<sub>2</sub>O<sub>3</sub> to B<sub>2</sub>O<sub>3</sub>) neopolymorphic transition''' <br> | ||
| + | Pure B<sub>2</sub>O<sub>3</sub> is slightly water soluble and toxic, so when going far with the forced substitutuion the parts must be perfectly sealed against humidity. | ||
== Related == | == Related == | ||
| − | * [[pseudo phase diagram]] | + | * [[pseudo phase diagram]] - mapping out neo-polymorphs |
| + | * [[Simple crystal structures of especial interest]] - browse there as a starting point | ||
| + | ----- | ||
* [[diamondoid compound]] | * [[diamondoid compound]] | ||
* [[binary diamondoid compound]] | * [[binary diamondoid compound]] | ||
| + | ---- | ||
| + | * [[Kaehler bracket]]s | ||
== External links == | == External links == | ||
| − | + | Wikipedia pages: | |
| − | * | + | * [https://en.wikipedia.org/wiki/Polymorphism_(materials_science) Polymorphism (materials science)] |
| − | * | + | * [https://en.wikipedia.org/wiki/Polymorphs_of_silicon_carbide Polymorphs of silicon carbide] |
| − | * | + | * [https://en.wikipedia.org/wiki/Isomer isomer], [https://en.wikipedia.org/wiki/Stereoisomerism stereoisomer], [https://en.wikipedia.org/wiki/Conformational_isomerism conformational isomer] |
| + | * [https://en.wikipedia.org/wiki/Superstructure_(condensed_matter) Superstructure (condensed matter)] | ||
| + | * [https://en.wikipedia.org/wiki/Isomorphism_(crystallography) Isomorphism_(crystallography)] | ||
| + | ---- | ||
| + | * Isotype: [https://www.mineralienatlas.de/lexikon/index.php/isotyp?lang=de (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: [https://de.wikipedia.org/wiki/Isotyp (wikipedia de) Isotyp] | ||
| + | ---- | ||
| + | * [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 | ||
Latest revision as of 10:41, 6 June 2023
A neo-polymorphic compound (or neo-isomorphic compound) is a highly stable non equilibrium polymorph of a material with a certain fixed stoichiometry that is exclusively accessible through mechanosynthesis.
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.
The patterns can be:
- different atom types (elements) ... 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.
- different stacking geometry or ... 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).
- ...
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
- AABBAABBAABBAABBAABB – neo-polymorph – wanted peculiarly ordered state – not thermodynamically accessible - but accessible via mechanosynthesis
Of course arbitrary many elements/layertypes/... are allowed. A,B,C,D,...
Note: Thermodynamic accessibility refers to all the crude processes available today (2020) that only allow to handle matter in statistical quantities: melting, mixing, cooling, pressurizing, irradiating, ... This explicitly excludes advanced mechanosynthesis.
Examples
See: pseudo phase diagrams for more details on this.
The rutile stishovite (TiO2 to strong SiO2) neopolymorphic transition:
The common mineral rutile and the rare mineral stishovite (made out of the two most common elements in earth crust) share the same crystal structure. The rutile structure.
Albeit rutile not drawing silicon into its structure naturally (meaning it's thermodynamically unfavourable)
(as can be seen with rutile occuring embedded in quartz https://commons.wikimedia.org/wiki/File:Rutile@quartz.jpg)
a forced substitution (at least to some degree) may very well be possible via mechanosyntheic means
and the resulting product base material may very well be highly (meta) stable at room temperature.
The quartz to "carbexplosoquartz" (SiO2 to solid CO2) neopolymorphic transition
Obviously CO2 very much likes to be a gas (small atomic radii => sp orbitals sticking far out => orbitals hybridize and form double bonds)
so if pure CO is even mechanosynthsizable it would be a very delicate and thus dangerous high explosive. A little bit of substitution of Si with C may be safely forcable via mechanosynthetic means though, despite that substitution is not naturally happening due to unvafourable thermodynamics. Maybe even as much as 50% of the silicon could be substituted with carbon without getting to something unstable and useless? Who knows.
The SiO2 to GeO2 and SnO2 neopolymorphic transition
Si has a bit more dissimilarity to the element above (C) than the elements below (Ge,Sn) with the exception of (Pb).
Like less relative difference in diameter, less difference in their dislike to form double bonds, less difference in their metallicity, ... .
So these elements may be substitutable in higher quantities. Though Ge and Sn are to rare to be of use as large volume structural base material.
Also Ge and Sn form rutile structure (argutite and cassiereite respectively), so they may instead be able to
tie into the aforementioned rutile stishovite neopolymorphic transition.
Lead (Pb) may very well already be way too different to Si to even be force substitutable making the resulting structures unstable at room temperature or even below.
Lead and tin are (and where) used in the floating glass production process because they don't like to mix too much (on their own volition).
Still a lot of unwettability and immiscibility may be possible to overcome via mechanosynthetic forcing.
Also there is lead glass (Template:TODO)
- The Si3N4 to beta carbon nitride C3N4 neopolymorphic transition
Both are high performance materials but beta carbon nitride is highly exotic even in its pure form today (2020). Beta carbon nitride may be of especial interest since when drawing solid building material form thin air alone The concentration of CO2 is the limiting factor and given more than halve of C3N4 is nitrogen and thus material may be drawable more than double the speed.
- The BN to AlN neopolymorphic transition
Pure AlN hydrolyzes with water, so when going far with the forced substitutuion the parts must be perfectly sealed against humidity.
- The tistarite to leukosapphire to diboron trioxide (Ti2O3 to Al2O3 to B2O3) neopolymorphic transition
Pure B2O3 is slightly water soluble and toxic, so when going far with the forced substitutuion the parts must be perfectly sealed against humidity.
Related
- pseudo phase diagram - mapping out neo-polymorphs
- Simple crystal structures of especial interest - browse there as a starting point
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
