Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [phase-transition]

A phase transition is a change in the nature of a phase or in the number of phases of a system as a result of a change in the external conditions. Examples: melting/freezing, vaporization/condensation, ferromagnetic transition, superconducting transition.

0
votes
0answers
25 views

Statistical Mechanics & Dynamical Systems

As a (theoretical) physics student I've taken (advanced) undergrad courses in both statistical mechanics and dynamical systems (which was purely mathematical, treatment of nonlinear differential ...
1
vote
0answers
19 views

Electroweak phase transition and finite temperature field theory formalism

We do our calculations in standard quantum field theory at zero temperature where we can derive pole mass and renormalized mass and ... Due to my understanding, pole mass is independent of any energy ...
0
votes
1answer
50 views

About the Maxwell Construction

From Wikipedia I'm reading Griener Walter Niese's book on thermodynamics. In the section about the Maxwell construction, It says: Because the internal energy is a state function, the difference is the ...
5
votes
3answers
137 views
+100

Non-uniqueness of the Order Parameter and its Critical Exponent

In the theory of phase transitions, an order parameter is usually defined as some quantity which distinguishes the two phases of the system by being zero in one phase, and non-zero in the other (see e....
1
vote
0answers
11 views

Dependence of melting/boiling on external electric or magnetic fields

$H_2O$ is a rather strongly polarized molecule ($\epsilon_r\approx 80$) and it is also diamagnetic ($\chi_m \approx -9\cdot 10^{-6}$). My question is how does the melting or boiling $p-T$ curve ...
1
vote
1answer
45 views

What is the order parameter of 2D generalized $XY$ model?

I'm now studying the phase transition of 2D generalized XY model. This model considered here has a mixture with ferromagnetic and nematic-like interactions, $$\mathcal{H}=-\sum_{\langle i j\rangle}\...
1
vote
1answer
75 views

Phase separation in physics

I would look to familiarize myself with the current literature of phase separation. If one can direct me to statistical/thermodynamics theories of phase separation. Has phase separation been ...
0
votes
1answer
23 views

What is role of nucleation centre in the formation of ice?

Water must be impure so that the impurities can act as nucleation centre for ice to form. What is role of nucleation centre? Why can not ice form with some nucleation centre.
1
vote
2answers
46 views

Estimation of specific heat of a solid

I'm investigating a material, that under high temperature-pressure conditions undergoes a phase transition. In order to correctly calculate the temperature, or even estimate a reasonable value, I need ...
21
votes
4answers
2k views

Why do ice crystals form from the top to the bottom of a bottle filled with supercooled water?

If I bang a bottle filled with supercooled water against a hard surface, the ice crystals form from the top to the bottom:$\hspace{50px}$$\hspace{75px}$–source. YouTube has videos showing this ...
0
votes
0answers
37 views

Order of phase transition in random walks

If we consider a random walk with step size distribution $P(s)\sim s^{-\gamma}$, we know the order of $\langle s^2\rangle$ changes at $\gamma=3$, while the order of $\langle s\rangle$ changes at $\...
0
votes
0answers
32 views

Where is the gauge symmetry in an ideal Bose gas?

It seems in the literature that there is a certain notion of a “macroscopic wavefunction” associated with a Bose-Einstein system (see this PSE answer) which exhibits a global $U(1)$-phase symmetry. ...
0
votes
0answers
27 views

Gravitational waves from first order phase transitions

After the discoveries of Gravitational Waves (GW), and no excitement from LHC data, many physicists are spending their effort in trying to do particle physics with the Gravitational Waves signals. ...
0
votes
1answer
77 views

Obtaining an expression for spontaneous magnetization in 1D Ising model with $H=0$ from the beginning

The usual trick to find the spontaneous magnetization for the 1D Ising model is to calculate the partition function $Z$ with the Hamiltonian $$\mathscr{H}=-J\sum\limits_{i}S_iS_{i+1}-H\sum\limits_{i}...
0
votes
1answer
38 views

Potts model equivalent to Heisenberg model

The mean-field equations for the three-state Potts model $$ \mathcal{H}=-J\sum_{\langle ij \rangle}\delta_{\sigma_i\sigma_j}\:,\qquad\sigma_i=1,\,2,\,3 $$ is equivalent to $$ \mathcal{H}=-J\sum_{\...
1
vote
3answers
65 views

Why do gas expand when heated?

So as a volume of gas is heated, the addition of energy increase the particles' kinetic energy. This only means that they are now moving faster right? I cannot relate this increase of kinetic energy ...
7
votes
1answer
443 views

What is so topological about topological phase transitions?

I am studying the KT-transition, which is called a topological phase transition. The phase transition is driven by vortices in a 2-D superfluid, where it is shown that at a critical temperature $T_c$ ...
3
votes
0answers
48 views

Gapless modes at the boundary between topological insulator and normal insulator

I am currently learning about topology in condensed matter physics. I think I understand most of how topological indeces come about and differences between Z and Z2 indeces and the symmetries that ...
0
votes
1answer
37 views

Is a paste a type of glue?

I just wanted to know the answer to this because of the idea of phases of matter, would a paste (or glue) drying count as a change between the states of solid and liquid?
3
votes
4answers
305 views

What are the differences between specific latent heat and latent heat?

What are the differences between specific latent heat and latent heat? As far as I know, latent heat is the heat required or released during the change of state, without change of temperature. So ...
3
votes
2answers
65 views

Critical point of a pure substance

What I've understood is no matter how much pressure we apply to a gas present at its critical temperature, it will never liquefy, and that there will be no 'distinction' between the 2 phases, liquid &...
0
votes
1answer
49 views

Why is the electrochemical potential $\mu$ constant in the phase transition?

I was studying thermodynamics and my book shows that the electrochemical potentials have to be equal in a phase transition and I can't understand why. (the book I'm using is Callen).
2
votes
1answer
54 views

Multiple Triple Points

I was reading Chandler's Introduction to Modern Statistical Mechanics and noticed a strange feature in one of the figures. The phase diagram in the image has two triple points; however, according to ...
3
votes
3answers
142 views

What mechanism at the microscopic level determines whether a system heats up or not?

When placed in an ordinary or a microwave oven, a beaker of water heats up except during boiling (i.e., a phase change involving latent heat). Now, suppose a system absorbs energy in such a way that ...
1
vote
0answers
42 views

Latent heat and and raising temperature [closed]

So in first order phase order transitions, the parcel of matter undergoing the phase change can release energy into its surroundings. However it is "latent" in so far it will not raise the temperature ...
2
votes
1answer
67 views

First order phase transition and latent heat

Usually in physics, first order phase transitions are phase transitions where the free energy potential's first derivative is discontinuous when differentiated by some thermodynamic variable such as ...
1
vote
1answer
56 views

Metropolis Monte Carlo Phase Transition for small systems

Metropolis Monte Carlo simulation for the argon liquid fails to reproduce correctly the pressure-temperature isotherm from the point of liquid-vapour coexistence: Why such a phenomenon appears ? The ...
0
votes
0answers
17 views

Loschmidt Amplitudes In Tight Binding Models

I am trying to understand the calculation in this paper which experimentally looks at dynamical phase transitions in a driven (shaken) haldene-like model. The definition of the Loschmidt Amplitude is ...
0
votes
2answers
41 views

What happens when the saturation pressure of a substance is greater than its actual pressure

I am facing difficulties with understanding the relationship with saturation pressure and the phase change (from liquid to gas) of a pure substance. Let's suppose I have some amount of water at p = 5 ...
2
votes
3answers
152 views

Confusion on real space renormalization group for Ising model on lattice

For the Ising model with only nearst neighbor interaction on square lattice, if we do the RG by integrating out half degree of freedom, then we would get a new Ising model with many kind of ...
1
vote
2answers
46 views

Phase transitions, external and internal pressure and boiling

Let's say I have an open container of liquid. According to what I have read, to get the liquid to boil, the vapour pressure has to equal the atmospheric pressure (or there about). I can understand ...
1
vote
1answer
56 views

Phase transtions. Why has Ehrenfest classification been replaced by modern classification?

Why did modern classification replace Ehrenfest classification? What are the advantages of the modern one?
0
votes
1answer
53 views

Mixture with a strange free energy curve

I have the following energy landscape for a binary mixture with a specie $1$ of volume fraction $\phi$ (it is composed for example of colloids) and a specie $2$ of volume fraction $1-\phi$ (for ...
1
vote
1answer
15 views

Overconstrained equilibrium binary mixture phase seggregation

Assume a binary mixture, with the component $A$ in concentration $c$ and the component $B$ in concentration $1-c$. The total energy $E(c)$ is thus given by a function of one variable $c$ (if we do not ...
0
votes
1answer
19 views

Interactions between “particles” to prevent diffusion and to cause phase segregation

The free energy of particles reads, if we assume no internal energy : $\tilde f(c)= \frac{f(c)}{k_bT}=-c \, ln(c)-(1-c)\, ln(1-c)$, with $c$ the concentration. If we had a term $F(c)$ for the ...
0
votes
2answers
23 views

Calculate an order parameter for a given set of atomic coordinates

I have a box which contains a few thousand atoms, and I would like to be able to calculate a single number which gives some indication of how ordered their arrangement is in 3D. For example, if they ...
0
votes
1answer
89 views

Melting gold at room temperature?

https://www.sciencedaily.com/releases/2018/11/181120125750.htm I'm skeptical about how the researchers claim that the gold melted at room temperature. Isn't what's really happening is that the ...
2
votes
1answer
84 views

Why are RG flow fixed points associated with different phases?

Why are RG flow fixed points associated with different phases? I thought the RG makes only statements about behavior near to critical points... a definite phase is far away from the critical point, ...
0
votes
0answers
73 views

What is finite size scaling theory?

The question is in the title. I read some articles about it but I could not understand it completely. What does it mean when we say scaling of any system? Can you please give a brief introduction ...
1
vote
3answers
119 views

Can Heat Transfer occur between two bodies with the same temperature but different states only through Latent Heat Transfer? [duplicate]

I understand that temperature difference is the driving force for heat transfer but I have been wondering whether there would be any heat transfer, let's say if steam at 100 degree Celsius and water ...
2
votes
1answer
75 views

Boiling water in metal pot

This is something I've observed when boiling water for tea. I place the water in a metal pot and bring it almost to a boil. The water level is at about the middle of the height of the pot. When the ...
1
vote
1answer
64 views

What is the difference between non-equilibrium and equilibrium phase transitions?

My question is about the distinction between certain kinds of phase transitions. I understand what the difference between first and second order ones are. What is the difference between non ...
2
votes
1answer
109 views

Mean field 3d Ising model in Landau theory

I am solving a problem for some course I am following. I am given the Hamiltonian: $$H = 3NJ \langle \sigma\rangle ^2 -6J\langle \sigma\rangle \sum_i\sigma_i,$$ where $i$ sums over all sites ($=N$)....
5
votes
1answer
67 views

What is the topology of a phase diagram?

Looking at various two-variable phase diagrams I was struck by that on every one I have seen so far all the phases formed simple connected regions; see, for example the phase diagrams of $H_2O$ or of $...
0
votes
1answer
78 views

What is direct interaction, if exist, between gluons and pions?

Gluons mediate the strong force between quarks. Pions mediate the nuclear force or nucleon-nucleon interaction or residual strong force. I had thought of some scalar bosons for my idea because if I'm ...
1
vote
2answers
54 views

Potential Energy of Particles

I read the following statement in my textbook While a liquid is boiling, the energy supplied to the liquid goes to breaking the bonds between neighbouring molecules. Can anyone explain the process ...
0
votes
2answers
88 views

Phase transitions and Helmholtz vs Gibbs Free Energy

Gibbs phase rule for Gibbs free energy says that phases during a phase transition must be in mechanical, chemical, and thermal equilibrium, e.g. $T_1=T_2$,$G_1=G_2$, and $P_1=P_2$, where the ...
2
votes
1answer
81 views

Why is it that all metals do not become superconductor by lowering the ambient temperature?

Aluminium becomes a superconductor at a temperature below $1.91$K. But I am quite certain that all metals do not exhibit superconductivity even when the temperature is lowered to nanokelvin or below. ...
2
votes
1answer
64 views

Melting ice inside water by increasing pressure

An ice cube is floating in water inside a container and the system is in thermal equilibrium. And let say we somehow immerse the ice cube slowly into deeper region inside the container (we may pull a ...
0
votes
1answer
33 views

Variation/Differential in Critical Radius of Homogeneous Nucleation

Getting the critical radius during nucleation from G(r) is straightforward - but in our lecture notes, a notation is used that I cannot quite wrap my head around: The molar Gibbs Free Energy $G(r)$ ...