I find this interesting : supercooling

[William Gaatjes]

http://www.sciencedaily.com/releases/2010/04/100421133114.htm

Supercooled liquids are trapped in a metastable state even well below their freezing point, which can only be achieved in liquids that do not contain seeds that may trigger crystallization. Clouds at high altitude are a good example for this: they contain tiny droplets of water that, in the absence of seed crystals do not form ice despite the low temperatures. In everyday life, though, there is usually some crystalline impurity in contact with the liquid that will trigger the crystallization process, and therefore the freezing. Controlling solidification behaviour is important for applications ranging from hail prevention up to technological processes such as welding and casting or even the growth of semiconductor nanostructures.

Supercooling was discovered already in 1724 by Fahrenheit, but even today the phenomenon remains a subject for intense discussions. Over the last 60 years the very existence of deep supercooling has led to speculations that the internal structure of liquids could be incompatible with crystallization. Models propose that a significant fraction of the atoms in liquids arrange in five-fold coordinated clusters. To form a crystal however, one needs a structure that can be repeated periodically, filling the entire space. This is not possible with five-fold coordinated clusters. In the two-dimensional analogue, a plane cannot be filled by pentagons only, whereas triangles, rectangles or hexagons can fill a plane perfectly. In this example, pentagons are an obstacle to crystallization.

Until today there was no experimental proof that this five-fold coordinated structures are at the origin of supercooling. The researchers from the CEA, CNRS and ESRF studied the structure of a particular liquid, a gold-silicon alloy, in contact with a specially decorated silicon (111) surface, where the outermost layer of the solid featured pentagonal atomic arrangements. Their findings confirmed that a strong supercooling effect took place. "We studied what happened to the liquid in contact with a five-fold coordinated surface," explains Tobias Schülli, first author of the paper. The team performed the control experiment with the same liquid exposed to three-fold and four-fold coordinated surfaces, which reduced the supercooling effect dramatically. "This constitutes the first experimental proof that pentagonal order is at the origin of supercooling," explains Tobias Schülli.

It was during their studies, originally focusing on the growth of semiconducting nanowires, that the scientists discovered the unusual properties of these liquids. As they were observing the first stage of growth of nanowires, they could see that the metal-semiconductor alloy they used remained liquid at a much lower temperature than its crystallization point and so they decided to investigate this phenomenon. These liquid alloys are popular in applied research as they enable the growth of sophisticated semiconductor nanostructures at low growth temperatures. Most of these nanowire structures are grown on silicon (111), the same surface used by the team. Semiconducting nanowires are promising candidates for future electronic devices. Prominent examples are solar cells, where scientists are working on the integration of silicon nanowires in order to increase their performance.

It reminds me of the empty space of the universe. And makes me think about how the formation advances from gas to liquid to solid and about fractals.


http://en.wikipedia.org/wiki/Fractal

EDIT:

I have always wondered about the self organization of matter. Every element has some self organization gong on. For example in empty space when hydrogen atoms combine, i always wondered what happens. With 2 hydrogen atoms it is relatively easy, but what about 3 ,4 ,5 etcetera. The reasons why i wonder about this, is because when looking at nature there is a lot of self organization.
And nature itself is not a conscious being, but relies on the properties of matter, meaning the properties of the elements.
I was thinking about the following idea :
There is a certain amount of chaos, unpredictability. But the laws of the universe provide a means of self organization that in any random situation a certain cause acts like what is called in the text above a seed. Now assuming there are no molecules and only atoms of the same element, what is the seed ? Isotopes ?

Anybody can give me some food for thoughts ?

 

[Mr. Pedantic]

Eh? What?

Hydrogen does not form H3 or H4 molecules, as far as I know it's physically impossible. The two allotropes of hydrogen that I know of are hydrogen gas, H2, and metallic hydrogen.

Other than that I have no idea what you're trying to say. Mind elaborating?

 

[mutz]

Anybody can give me some food for thoughts ?

nature itself, as human species is part of it,
is very conscious...
and order,
it doesn't mean we see it...

Hydrogen does not form H3 or H4 molecules, as far as I know it's physically impossible. The two allotropes of hydrogen that I know of are hydrogen gas, H2, and metallic hydrogen.

maybe this :
http://en.wikipedia.org/wiki/Hydrogen-5
http://en.wikipedia.org/wiki/Hydrogen-4
http://en.wikipedia.org/wiki/Hydrogen-3

btw,
very interesting post .

E:
yet what do you suggest are the application of such research?
reaching absolute zero (or close to it) with better designed cooling substances, or being able to cool better 5-fold nanoscale devices?

 

[Mr. Pedantic]

maybe this :
http://en.wikipedia.org/wiki/Hydrogen-5
http://en.wikipedia.org/wiki/Hydrogen-4
http://en.wikipedia.org/wiki/Hydrogen-3

btw,
very interesting post .

Maybe you misunderstood me. When I said allotrope, I meant allotrope. I did not mean isotope. And neither did he.

E:
yet what do you suggest are the application of such research?
reaching absolute zero (or close to it) with better designed cooling substances, or being able to cool better 5-fold nanoscale devices?

Perfect lubricants?

 

[mutz]

Maybe you misunderstood me. When I said allotrope, I meant allotrope. I did not mean isotope. And neither did he.

i'm hard with the difference..

Perfect lubricants?

perfect i.e?

 

[jimhsu]

perfect i.e?

Frictional coefficient = 0? Newton's 1st law actually holds literally (in a vacuum)?

 

[mutz]

Frictional coefficient = 0? Newton's 1st law actually holds literally (in a vacuum)?

exactly,
this is fascinating,
creating a perpetual motion -energy balanced- machine.
reaching absolute zero, etc.

yet this has some constraints in it, won't it..?
if we manage to create a true closed system, then where would the energy to operate such system would get injected from?

or rather, there would be a system, that once it is closed, it is naturally changing it's own state and thus creates it's own energy to function..:hmm:..

maybe that is possible :hmm:.
can't tell .