# Tag Info

## New answers tagged phase-transition

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The classical situation with no symmetry breaking is the case of the, so-called, isostructural transitions. The word "isostructural" is misleading, since what is meant is "isosymetric". However, historically the term emerged. There is a number of examples of such transiotions. One is the alpha-alpha' transitions in the hydrogen-metal systems, another is ...

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I will not directly answer your question, rather I'll try to make plausible the connexion between QFT and statistical physics. To my mind the mathematical details are somehow obscure and confusing, whereas using the theory is worth a deal, and give interesting results, especially in condensed matter and nuclear matter problems. For more details you can have ...

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The term you are looking for is premelting or "surface melting." It is an observed phenomenon (which could explain how ice skating works) with some thermodynamic descriptions. Basically what happens is the system is separated into two distinct phases, a solid (ice) and a vapor (air). There is a surface energy associated with this interface. If it happens ...

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In other words, for, say, an elemental solid, should we expect a portion of its surface to be liquid at any given time, with this portion increasing steadily until the melting point when the whole thing becomes liquid? It is possible for many compounds be part solid and part liquid under the right conditions. As ice melts, you have this condition. ...

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It depends on the walls. If they are truly insulated, no heat will flow in or out. The water that freezes raises the temperature, while the water that evaporates lowers the temperature. The triple point of water is $0.01^\circ C, 611.73$ Pascals. If the chamber is very large, relatively much of the water will evaporate and the temperature will be below ...

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When one says the boiling point is x degrees at such a pressure, what it means is that it holds a partial vapour pressure up to this. Heat is fed in to make water into steam, even at room temperature, but it's so slight you don't notice it in the speciic heat. When you have a large volume, a large amount of water is turned into steam, until the correct ...

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Let me answer your first question: Phase transition do not necessarily imply a symmetry breaking. This is clear in the example your are mentioning : The liquid-gas transition is characterized by a first order phase transition but there is no symmetry breaking. Indeed, liquid and gas share the same symmetry (translation and rotation invariance) and may be ...

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Only first-order phase transitions involve latent heat (http://en.wikipedia.org/wiki/Phase_transition#Modern_classifications ). In general, thermodynamic variables can have singularities in phase transition points.

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An electric field is not experimentally known to change the equilibrium freezing point of water of 0 C. However, water can be supercooled to -40 C, in the absence of nucleation sites. Electric fields affect the freezing of (unstable) supercooled water. See this 2010 article in the journal "Science": http://www.sciencemag.org/content/327/5966/672 and ...

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Enthalpy (H) is the internal energy (U) of a material PLUS the product of pressure (P) and volume (V). $H = U + PV$ by definition When something boils, the gas phase takes up more volume than the liquid phase. So unless the boiling is in a vacuum, work is being done by expanding against a pressure, such as atmospheric pressure. This represents a change in ...

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