What is Phase transition: Definition and 60 Discussions

In chemistry, thermodynamics, and many other related fields, phase transitions (or phase changes) are the physical processes of transition between the basic states of matter: solid, liquid, and gas, as well as plasma in rare cases.
A phase of a thermodynamic system and the states of matter have uniform physical properties. During a phase transition of a given medium, certain properties of the medium change, often discontinuously, as a result of the change of external conditions, such as temperature, pressure, or others. For example, a liquid may become gas upon heating to the boiling point, resulting in an abrupt change in volume. The measurement of the external conditions at which the transformation occurs is termed the phase transition. Phase transitions commonly occur in nature and are used today in many technologies.

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  1. codebpr

    A Symmetry breaking in the AdS small/large black hole phase transition

    I am trying to reproduce the results from this paper where they find out the expression for the Landau functional to be $$\psi(x,t,p)=\frac{1}{4}(\frac{1}{x}+6x+px^3-4tx^2)$$ We plot the Landau functional v/s the order parameter($x$) at $p=0.5$ and obtain the Figure 4. from the paper as Now...
  2. S

    I Topological phase transitions for the whole Universe...?

    Physicist Grigory Volovik has put forward some ideas about the universe undergoing a topological phase transition (especially in the early stages of the universe). He published a book called "*The Universe in a Helium Droplet*" where he explained his ideas. You can find a brief discussion here...
  3. negarina

    Can a single-phase solid solution have a martensitic transformation?

    I'm trying to investigate the possibility of martensitic transformation in a non-iron alloy, described as a single-phase alpha-solid-solution (Nickel-Silver CuNi12Zn25Pb1, CW404J). I know that Cu-Ni-Zn alloys with higher zinc amounts show even shape memory effects. And that CuNi12Zn25Pb1 is no...
  4. B

    Finding transition temperature of Landau ferroelectric

    So for part a, I separately minimized F wrt ##\theta## and ##P## and got the following. $$\frac {\partial f} {\partial \theta} = a_{\theta}(T-T_{\theta})\theta + b_{\theta}\theta^3 - tP = 0$$ $$ \frac {\partial f} {\partial P} = \alpha(T-T_P)P -t\theta$$ $$ P = t\theta \alpha (T-T_P) $$ Then...
  5. N

    A What are the methods for calculating quantum phase transition?

    Trying to understand what the math methods are exist to determine quantum phase transition and how I can calculate it, by what methods.
  6. R

    A What Are Examples of Exotic Order-Disorder Phase Transitions?

    I am looking for possible examples and a variant of Landau's theory of phase transitions for an exotic order-disorder phase transition, in which a thermodynamic system jumps into a disordered (or less orderly) state by reaching the maximum critical value of the order parameter. That is, in one...
  7. Daria

    How Do You Calculate Phase Transition Thermodynamics?

    Hello! I'm struggling with this exercise for three days already. Would appreciate any help. Thanks in advance. This is my thoughts... So a number density ρ=N/V. As I understand N doesn’t change through transition, but V changes The free energy F=U-TS or dF=-PdV-SdT As the liquid coexists...
  8. C

    Proof of second-order phase transition for a Van Der Waals Gas

    How is it proved that Van Der Waals gas is a second order phase transition? The second order derivative of the pressure (P ) with respect to volume ( V ) don't have a discontinuity ( except at point V = Nb , but the pressure is not existent for V<=Nb ). So how come Van der waals gas describes...
  9. Diracobama2181

    Van Der Waals Phase Transition

    Not sure where to actually start. Do I need to do a virial expansion? Any tips on on where to start would be greatly appreciated.
  10. H

    I Is an atomic electron transition a phase transition?

    Is atomic electron transition a phase transition? https://en.m.wikipedia.org/wiki/Atomic_electron_transition
  11. Baibhab Bose

    Phase transition between two phases with different Cv

    I actually can't figure out what kind of phase transition it is and how to proceed through..!
  12. T

    Solving Ising Spin 1 Model w/ Transfer Matrix Method

    I did the first part using the transfer matrix method: $$ Z = Tr(T^{N}) $$ In this case, the transfer matrix will be $$ T(i,i') = \begin{pmatrix} e^{\beta J} & 1 & e^{-\beta J}\\ 1 &1 &1 \\ e^{-\beta J} & 1 & e^{\beta J} \end{pmatrix} $$ To get the trace of $T^N$, you find the...
  13. N

    A Phase transition under pressure?

    hello everybody does always phase undergoes transition when a pressure applied on a crystal ?even when the temperature is constant? and can pressure be increased without increasing temperature for a crystal? best regards Nawzad
  14. C

    Heat Capacity relations for 1st order phase transition

    Homework Statement Prove the following relation for which clausius equation holds : Cs=Cp-αV(ΔH/ΔV) Where Cs=∂q/∂T at constant S and is the heat capacity in the coexistence line of 2 phases Homework Equations dq=dU+dW dP/dT=ΔH/(ΔV*T) The Attempt at a Solution I do not fully understand why q...
  15. H

    A Do thermal quantities change in quantum phase transition?

    Such as, Chern insulator, normal insulator, topological insulator, do they have any discontinuous change in thermal quantities? Do they have order parameters?
  16. F

    I Liquid-gas phase transition: metastable mixed states?

    Hello everybody. I am trying to understand better what happens at a liquid-gas phase transition for the Van Der Waals model. From what I have understood, from the Van Der Waals model we are able to plot the curve P(V) and to calculate the free energy F. Here are such curves : Then, we...
  17. V

    I Inflation as a phase transition

    Hello, I have heard that one of most acceptable theory (or hypothesis) describing the inflation phase of universe is that energy to this stage is drawn from phase transition when strong interaction is separated from "preinteraction" (when all interactions were undistinguishable) Do you agree...
  18. C

    I Scale invariant thermal fluctuations

    There's something that has been bugging me for over a year now and I seem to be unable to find the answer. I would appreciate it very much if somebody could help me out. The thing is that I don't understand how it is possible that in second order phase transitions the correlation legth becomes...
  19. FranciscoSili

    Finding Mole Fractions in a Two-Phase Equilibrium System

    Hello everyone, I'm doing revision for a final exam in Thermodynamics and i found this exercise i can't solve: A particular material has a latent heat of vaporization Δh, constant along the coexistence curve. One mole of this material exists in two.phase (liquid-vapor) equilibrium in a...
  20. C

    I Cosmological electroweak phase transition

    There is a question that has been bugging and puzzling me for a long time and I wondered if somebody could help me to figure out what the answer is or where I am not thinking straight. Let us assume that the standard model of particle physics is more "right" than "wrong" and there is no such a...
  21. C

    I Phase transitions university classes

    There's something that I'd like to know and haven't been able to find in any book: 1.- Is the number of second order phase transition university classes known? 2.- Do we know quantitatively know the behavior of all such second order phase transition university classes? 3.- Do we know the...
  22. DrClaude

    Phase transition in rotating balls

    A very neat video showing a phase transition in rotating balls in a cup. Serves as a good analogy to other phase transions.
  23. C

    A Do cosmologists take spontaneous symmetry breaking seriously?

    I suppose that my questions are pretty basic, but I've been trying to find out the answers and not succeeded. 1.- Do cosmologists really think that the vacuum state suddenly changed in the early Universe? If so, would it be like a phase transition? If so, first or second orther? 2.- Does the...
  24. G

    A Why does Finite Size Scaling shift the Phase Transition Down?

    See the title. I'm not sure that this is the right place to post this question, but I'm not sure it fits any better on any of the other boards. Let's say you have a phase transition. The correlation length will scale as: ξ = |TC-T|ν This diverges on both sizes of the phase transition. Now...
  25. T

    B Could a black hole involve a phase transition?

    The reason I ask is that the singularity involves a region of spacetime composed of a different order of magnitude than i suppose the region outside the singularity.
  26. T

    A What do people mean by "dynamical phase transition"?

    I heard of it several times in colloquiums. But I still cannot grasp the meaning. What is the control parameter in this phase transition?
  27. M

    Phase transition at high energies?

    Hi,I'm new here, and created my account solely for following question: Does the incompatibility between QM and Relativity indicate a phase transition at high energies? (as in: indicate more than a "could be")
  28. TheOfficialAB

    Crystal phase transition, Diffraction peak splitting problem

    Homework Statement [/B] Hi there! This is a question from a practice problem sheet I got from the lecturer of my Condensed Matter 1 course. Below are the normal vectors to the {111} and {112} lattice planes: Homework Equations [/B] Bragg Condition: \begin{equation} n \lambda = d \sin...
  29. G

    What is a phase transition in the context of an ising glass?

    The wikipedia article mentions that the model allows for "phase transitions" but doesn't specify what it means by this? What is a phase transition in the context of an ising spin glass? Is it when the mathematical model of a magnet, changes from solid to liquid? In this paper...
  30. D

    The difference between order parameter and state parameter?

    At first, we need some state parameters(like P/T/V) to fully describe a system. And the order parameter is also a parameter which could describe the property of the system. However, in the Laudau theory, why it said that order parameter is an external parameter(not a independent variable)? Is...
  31. A

    What is a topological phase transition and how is it characterized?

    I have just been reading a classical paper on the formation of majorana edge states (MES) in quantum wires. The hamiltonian is Kitaev type with a superconducting and spin-orbit interacting and one finds that the energies have a gap that closes and reopens as we vary the magnetic field. According...
  32. J

    Condition for Phase transition

    Hi I'm trying to use Peierl's argument which in essence is clear to prove that there does exist a phase transition in the 2D Ising model without external field. The issue I'm having is of a more mathematical nature, in class it was mentioned that there is a phase transition if for some ##\delta...
  33. lfqm

    Different orders for a phase transition (variable depending)

    Hi guys! I've got this system in which Eherenfest classification of "order" is assumed to be ok. So I took my free energy function G(T,P) and start differentiating. I found just one phase transition between two phases, the problem is the phase transition is of different order depending on the...
  34. pedroall

    Order Parameter in a Gauge Theory, Can we find one in a Gauge Theory(like QCD)?

    Hello Community! I can't find a good answer(if there is) to my question. When in statistical mechanics we can define the order parameter for to study some phase transition. we need to define a order parameter. Now, I want to know if we can to define/find some "order parameter" for to...
  35. R

    Why is the enthelpy of a phase transition different from 0?

    Hello, Wikipedia states: Phase changes, such as melting or evaporation, are also isothermal processes. I am interested in calculating the enthalpy of a given phase transition. If the process is isothermal, I would immediately say that H is 0, according to the following equation: dH=CpdT...
  36. A

    Are Phase Transitions Caused by Instabilities or Spontaneous Symmetry Breaking?

    So a phase transition occurs when a system may minimize its free energy by spontanously breaking some symmetry. At least that is what I have learned from my current course so far. However I also did another course concerning phase transitions. In this case phase transitions were always...
  37. S

    Temperature of phase transition

    Homework Statement There is a solid that can be in two phases, with energies U1(S,V) = S2/a1 + b1V(V-2Vo) and U2(S,V) = S2/a2 + b2V(V-2Vo). Consider a phase transition between the two phases at zero pressure. At what temperature, T0, does it occur? Homework Equations T = ∂G/∂S...
  38. J

    Prandtl number of a g/l mixture (Ethane at phase transition)

    I have a problem in finding the heat transfer coefficient of a heat exchanger in which Ethane undergoes a phase transition. I would like to find the Prandtl number of Ethane in the phase transition region. So far I thought I would use the following: Pr_av = x * Pr_g + (1-x) Pr_l Pr_av =...
  39. B

    Why do some P,T sets of data give wrong readings in phase transition problems?

    Homework Statement http://icho2013.chem.msu.ru/materials/IChO-2013_Theoretical_Official_English_Version.pdf Looking at problem 1. Homework Equations The integrated form of the Clausius-Clapeyron equation: ln(\frac{P_{T2}}{P_{T1}}) = -\frac{\Delta H}{R} \cdot (\frac{1}{T_2} -...
  40. B

    Expressing Rates of S's Phase Transition: P1, T1, and Activity of S (Phase 1)

    Let's say I have a general phase transition S (phase 1) ::equil:: S (phase 2). At a certain point in pressure and temperature for each phase (they can have different pressures and temperatures, we might say P1 and T1 for phase 1 and P2 and T2 for phase 2), how might we express the forward and...
  41. hilbert2

    One-particle system with phase transition?

    Hi, I'm Teemu from Finland, and I'm just getting my master's degree in physics completed (only one course in electronics left). This is my first post in Physicsforums. I was thinking about a problem in statistical mechanics. As you all know, if we have a one- particle system where the...
  42. T

    Finding Ionizable Phase transition agent with low phase change energy

    Hello everyone, I'm designing an experiment which utilizes a single agent in different phases (liquid, gas, and plasma). The apparatus needs to be able to ionize the gas into a plasma (with +/ - 1 or more electrons). I'm trying to keep energy consumption at a minimum, so current phase...
  43. R

    During a phase transition, what is the nature of the material?

    As a material is heated, it increases in temperature until it enters a phase transition. During the transition, added heat does not increase the temperature. As this heat is being added, what is the substance? Is it a mixture of liquid and gas perhaps? If so, what are the proportions? In...
  44. S

    Gross Perrywall phase transition

    I just watched a video of James Gates and he discussed something he called the Gross Perrywall phase transition. It was named after David Gross, I am assuming most of you are familiar with his work. In an attempt to search more about this I came up empty. I do not know if I am spelling it...
  45. F

    What Causes the Earth's Crust-Atmosphere Phase Transition?

    Hello, I ask for your help because I can't find any information about Earth crust-atmosphere phase transition. I noticed indeed that our feet tread upon a solid surface, while our nostrils breath a gazeous compound ! This remark seems so obvious that I can't find any description neither...
  46. R

    The phase transition of the universe during inflation

    This is from Krauss' A Universe from Nothing: It seems like he's saying that before inflation kicked in around 10^-36 or 10^-34 I forget which that the universe, I'm guessing from 10^-43 - 10^-36 was in some sort of false vacuum state, analogous to the way matter changes phase from gas to...
  47. W

    Condensed Matter Super-Radiant Phase Transition

    Is anyone familiar with this or heard of this concept before? It started in 1953 by a paper by Dicke published in peer reviewed Physical Review Journal called "Coherence in Spontaneous Radiation Processes" http://prola.aps.org/abstract/PR/v93/i1/p99_1 Then in 1973 Hepp and Lieb published...
  48. O

    Does THERMODYNAMIC process affect phase transition in solid state metals

    I was reading an article about phase transition, i read about thermodynamic process such as Adiabatic process - a process with no heat transfer into or out of the system. Isochoric process - a process with no change in volume, in which case the system does no work. Isobaric process - a...
  49. I

    Help needed on calculating system pressure during rapid phase transition of CO2

    Dear Members, I am strugling with calculations on rapid phase transition (RPT) of CO2 in a high pressure vessel. I looked everywhere, from isochoric data to ...you name it but can't get there... The question: What will the resultant pressure be when solid or liquid CO2 in area A contacts...
  50. A

    Phase transition in one dimension

    Hi, I was listening to Susskind's lecture on statistical mechanics (lecture 8). He mentioned in relation to Ising model of magnetized spin systems that there could not be any phase transitions in one dimensions. He mentioned that it has to do with the stability of the system. Can anybody...
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