# Talk:Spinodal decomposition

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## Phase diagram

I have presently restored the phase diagram section. Is there a reason it was removed or was this an accident? Locke9k (talk) 21:52, 7 May 2009 (UTC)

I have now also restored the free energy diagram of the spinodal, but made much smaller than before. Maybe it was removed because of its excessive size? This is probably the most commonly shown and also most explanatory diagram for the nature of the spinodal, so it seems like something of this nature belongs in the article. Locke9k (talk) 21:57, 7 May 2009 (UTC)

I'll also note that I think this article needs a lot of work; I am planning to do some significant work on it soon. Locke9k (talk) 21:58, 7 May 2009 (UTC)

Hello there ! I checked out your background, and it definitely looks like we have some common interests. With a background in MS&E, I recently authored the pages on Sol-gel, Physics of glass, Glass transition, Strength of glass, Transparent materials and Phase transformations in solids among others. I am very interested in Spinodal decomposition, and will be meeting with Dr. John Cahn on the UW campus next week to discuss the possible applications of his theories to my own work in Colloidal crystal formation.
I will be adding quite a bit to this article over the next few days, begining with the diffusion equation, and moving forward from there to the Fourier transform applications. I will not be doing any work in k-space, however, so that portion remains as your regime. Personally, I do not think that both phase diagrams are necessary. I think that the article is more effective with just one (less distraction, more focus). But I certainly will not object if you choose to put it back in. I think the one I posted with the inflection points is the one most widely referenced, and includes all the necessary information needed to establish the main concepts.
It's great to find someone else who shares common interests in this particular subject. I have been interested in Cahn's theories for nearly 30 years now. I am only now finding the time to explore them in further depth :-) -- logger9 (talk) 06:36, 8 May 2009 (UTC)

## Equations should be in math code

Many equations here are image files, but mathematics should be written using $formula$ code. I found these formulas on commons:category:Particle physics, where they clearly not belong. So please convert, and have these images deleted. /Pieter Kuiper (talk) 15:39, 6 June 2009 (UTC)

Done. Please confirm that I have not introduced any errors in the transcription. User A1 (talk) 04:51, 7 June 2009 (UTC)
Thanks, guys ! Sorry, but I don't know the math codes yet (I am just a lowly materials science engineer), so I had a desktop publisher create the images to save time. I have a regular email dialogue going with Dr. John Cahn, who I met some 25 years ago at a grad school seminar. We will be meeting again soon on the UW Campus in Seattle to discuss his latest theories and current experiments, where he is pulling glasses from the melt and attempting to show that the glass transition is an example of the first-order phase transformations in solids. Wish me luck :-) -- logger9 (talk) 18:57, 8 June 2009 (UTC)

## Math issues

I fixed the equation ${\displaystyle D=\mu \partial f/\partial {c}}$, figuring it was just a typo, but it was reverted. I'm not going to change what is there now, but I'll explain the issue. In instances where ${\displaystyle \mu }$ is used, the relative chemical potential is implied.

From

${\displaystyle J=-D\nabla c=-M{\frac {\partial ^{2}f}{\partial c^{2}}}\nabla c}$

we're saying that ${\displaystyle D=M\partial ^{2}f/\partial c^{2}}$. We know that ${\displaystyle \partial f/\partial c=\mu }$ from the differential of the free energy (this is stated several lines down in the article), and so

${\displaystyle D=M{\frac {\partial \mu }{\partial c}}.}$

This derivative of the chemical potential with respect to concentration is proportional to what is called the thermodynamic factor. A lot of the notation looks like it was pulled from the review by Hilliard, but I can't point to that for this, because he doesn't actually include this relation.

Aside from that, there are some inconsistencies in notation (e.g., confusion between ${\displaystyle \mu }$ and M for mobility and an instance where f is used where c is meant). It seems like people are keeping tabs on this article, so I won't mess with it. Just thought it should be cleared up so as not to mislead anyone who is new to the subject. --VinnyTheFish (talk) 05:28, 23 November 2009 (UTC)

## Applications / Awards

The introduction lists two characteristics of spinodal decomposition -

1. Numbered list item it has a sound theoretical basis
2. Numbered list item it leads to practical applications.

While the first point appears to be explored fully (the math is impressive if obtuse to most of us), the second point appears to be given no development whatsoever.

Finally, today's (10-Nov-2011) announcement of a Kyoto prize for Dr. Cahn should be added to the article. — Preceding unsigned comment added by 98.237.176.169 (talk) 16:23, 10 November 2011 (UTC)

## Relationship to LCST and UCST pages

It seems from an outsider's perspective that this page has significant overlap with the Lower Critical Solution Temperature and Upper Critical Solution Temperature pages. As far as I can tell, the concepts and physics are the same but this page refers mostly to mineral and metal systems while the other two pages refer mostly to organic systems. It would be nice to see them somehow connected. I only know as much as I've read from the pages though so I'm not at all qualified to actually do it. — Preceding unsigned comment added by 73.229.125.70 (talk) 21:02, 4 September 2015 (UTC)

## History issues

"Becker and Dehlinger had already predicted a negative diffusivity inside the spinodal region of a binary system."

Is there a reference that clearly supports this statement?Wikibearwithme (talk) 07:41, 24 December 2015 (UTC)

## Assessment comment

The comment(s) below were originally left at Talk:Spinodal decomposition/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

 Is spinodal decomposition the correct description of the process by which two compounds can be separated by means of rapid freezing and thawing? Or is the process in question a hetereogeneous seperation?

Last edited at 10:12, 7 September 2008 (UTC). Substituted at 06:43, 30 April 2016 (UTC)