morsagh
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Glass state
Is glass supercooled liquid or is it cryptocrystalline solid? Any reference that says why?
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DraconicAcid
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It's a solid that have the same random internal structure as a liquid.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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morsagh
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Some reference or method to prove it?
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careysub
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An authoritative work on the subject (and many, many others) is Kittel, "Introduction to Solid State Physics":
https://ia801605.us.archive.org/2/items/IntroductionToSolidS...
He treats glasses in the chapter on "noncrystalline solids".
The intro to this chapter states:
"The terms amorphous solid, noncrystalline solid, disordered solid, glass,
or liquid have no precise structural meaning beyond the description that the
structure is "not crystalline on any significant scale." "
Further:
"A glass has the random structure of the liquid from which it is derived by
cooling below the freezing point, without crystallization. Also, a glass has the
elastic properties of an isotropic solid. "
Note that that last sentence. By the "duck test" it is a solid.
Solid state physics typically considers that when a liquid reaches a viscosity of 10^13 poise on cooling is transitions into the glass state (this is
its effective "freezing point"). Glass can still undergo strain relaxation at this viscosity over the course of minutes, at 10^14.5 poise it takes
hours or days for strains to relax. At room temperature the viscosity of glass is on the order of 10^20 poise, a number so high that it cannot really
be measured.
Even crystalline metals, solid by every definition and convention, undergo strain relaxation at annealing termperatures, and soften so that they
deform easily, and soft metals will deform at room temperature (try holding up a strip of pure lead by its ends).
So yes, glass is a solid with the structure of a liquid.
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Texium
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Thread Moved
22-12-2015 at 08:10 |
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