Talk:Magnetic susceptibility

Susceptibility versus Relative Permeability

The discussion about the susceptibility is to know where it is inferior or superior to 1 and not positive or negative.

I think the article is correct as it stands in speaking about the distinction between χ positive versus negative. The permeability of the material depends not on χ alone, but rather on ( 1 + χ ). This factor is called the relative permeability of the material. So if χ is positive, the relative permeability is greater than 1; and if χ is negative, the relative permeability is less than 1. I am not 100 percent sure, but could that answer the concern that you have raised? -- Rdrosson 23:52, 21 October 2005 (UTC)

All right, but as you first wrote it, it wasn't that clear. Good job!

Mistake on this page. The magnetization is defined as magnetic moment per unit mass. It should be magnetic moment per unit volume. (Check the units). Also would be nice to link magnetic dipole moment (to Magnetic moment).

I don't believe the article should start of "In electrical engineering." Magnetic susceptibility is a physical parameter independent of any discipline. If it is tied to any discipline it should be physics but in general the article shouldn't tie susceptibility to any parameter.

Note that these are not all universally true. They require a dielectric material to provide the chi values, and therefore the kappas. So, if you're in a vacuum, they won't be true necessarily. —Preceding unsigned comment added by PurpleMonkey13 (talk • contribs) 18:35, 25 June 2008 (UTC)

Values of Volume Magnetic Susceptibility of Pure Water

According to the book "Spin Dynamics: Basics of Nuclear Magnetic Resonance" by M. H. Levitt, the volume magnetic susceptibility of pure water is $-90x10^{-6}$ in SI unit. In the current (11 April 2006) Wikipedia article, it appears that the susceptibility value is $-5.72x10^{-6}$ in SI and $-7.19x10^{-7}$ in cgs. Compared to the value in Levitt's, the cgs value makes sense, but the SI value do not. In fact, the number 5.72 might have come from $7.19/{4\pi }$, which is wrong calculation -- division instead of multiplication, combined with a wrong order of magnitude. Overall, I think the SI value in the Wikipedia article should be corrected to the value in Levitt's book, $-90x10^{-6}$.

Recent Edits introducing Intensity of magnetization

Please see the following forum for discussion of the notion of Intensity of magnetization. Recent edits by BehzadAhmadi had a number of errors, for example: the units in the first equation, $\mathbf {I} =\chi _{v}\mathbf {H}$, were not consistent, since $\chi _{v}$ is normally defined as a dimensionless quantity. Therefore, to avoid any more confusion in this historically confusing area, the edits were reverted to the last correct version. Xenonice (talk) 03:14, 23 January 2008 (UTC)

Recent edit of volume susceptibility definition

Somebody (130.88.52.80) "corrected" one of the volume susceptibility formulae to be

$\mu =1/(1-\chi _{v})\,$ ,

as opposed to the standard definition

$\mu =\mu _{0}(1+\chi _{v})\,$ .

Please refrain from such edits in the future (i.e. edits that replace an established formula with another that directly contradicts it), it would be better to discuss such changes here first. Xenonice (talk) 03:14, 23 January 2008 (UTC)

Wrong values

In the table, given values of density seem to be wrong. For exemple density of dioxygen O2 is very low and does not correspond to the standard value, which is 1,429 g/L (see article about oxygen). Guérin Nicolas ^(messages) 15:05, 11 August 2010 (UTC)

the value given in the article is at the partial pressure of oxygen in the atmosphere, about 20% of atmosphere. You probably refer to the density of oxygen at STP. Xenonice (talk) 00:51, 16 November 2010 (UTC)

table in example section: units wrong

In the article it is said that in CGS units the susceptiblity is unitless, yet in the table it has (emu) as the unit at the top. Inconsistent.

Magnetic Susceptibility Value for Water

The magnetic susceptibility value given in the table for water at 20 degrees is referenced to a paper in the Journal of Chemical Physics, which does not actually have data for all of the values. This paper is about a theoretical model for chi given the basis set, and compares to one set of experimental data. Hence, this needs another reference with a full set of data, preferably from a more modern source due to advancement in the field of measuring equipment. — Preceding unsigned comment added by 147.188.38.236 (talk) 11:38, 19 March 2013 (UTC)

I agree with this comment. In addition, I have tried to find these values in the article and could not find exactly any of them. Bongw (talk) 16:38, 16 July 2021 (UTC)

Rework For Kappa?

A different system of measurements exists for magnetic susceptibility, which is based on the defining relation:

M = κ(μ_oH)

rather than:

M = χH

relating the two systems to each other,

κ = χ/μ_o

This system is not officially recognized under SI, but it's an accepted standard for some sub-disciplines. It returns volume susceptibility with units (J/(T²m³) or H/m, and subsequently integrates units of energy and magnetism into mass and molar susceptibility.

See pages 6 & 7 of: Magneto-Science: Magnetic Field Effects on Materials: Fundamentals and Applications, Ed. Masuhiro Yamaguchi, Yoshifumi Tanimoto, Springer, May 11, 2007 (available as an ebook)

There are strong arguments for using the system as a convention. But without wading into that debate, it exists, is widely used, and is a necessary topic for people who encounter such data. Will change as little as possible in integrating it into the page.

--Regniweol (talk) 21:05, 24 October 2013 (UTC)

magnetization per volume and magnetization per mass

SQUID magnetometer in magnetization is measured per unit mass and if we use, for example, the Law of Approach to Saturation magnetization to describe the magnetization as a function of magnetic field, it is necessary to use the equation that relates M (mass) and M (volume) by the sample density. Is there any reference to the validity of this equation?. Thank you.201.209.78.191 (talk) 06:23, 12 June 2014 (UTC)Orlando

Partial deletion by User:Jytdog

Two days ago, User:Jytdog deleted half of the article due to a "edit war", and because he believed the section detailing the difference between the SI and CGS definition of susceptibility was a "howto". IMO, there was no edit war, apart from some minor squabbling over whether to write the greek letter rho using LaTeX or directly using Unicode. This does not change the meaning of the content, and arguing that this means that the content is "disputed" is not correct. Regarding SI vs CGS, it is a fact that we in physics use two different unit systems. Since the definition of the susceptibility differs by a factor of $4\pi$ between the two unit systems, it is NECESSARY for this article to a) declare what unit system it uses and b) give the definition in the other unit system as well. As for the information being "unsourced", any entry-level magnetism textbook can be cited, including O'Handley: Modern Magnetic Materials, Kittel: Introduction to Solid State Physics or Spaldin: Magnetic Materials - Fundamentals and Applications. 129.241.86.241 (talk) 11:38, 29 May 2015 (UTC)

I've gone ahead and tagged those sections for unsourced. Please source them, or they will need to be removed. As you appear to have expertise in this field, I urge you to read WP:TECHNICAL and make this article into an encyclopedia article. I have been considering nominating it for deletion for a while now, and still may do if the issues are not addressed. Thanks. Jytdog (talk) 12:39, 29 May 2015 (UTC)

I've added a source for the definition of volume susceptibility, which should serve as a source for that entire section. Sadly, I don't have time to do a complete rewrite of the article at this point in time, but I'm hoping that it can survive until someone (perhaps me) has time to look at it in the future. I only edited the article yesterday because I noticed that it was completely missing a section on volume susceptibility, and the first paragraph said "There are two other measures of susceptibility"... 129.241.86.241 (talk) 09:54, 30 May 2015 (UTC)

beautiful - thanks! we love WP:EXPERTs and need more of them who are willing to write encyclopedia articles - I hope you consider creating an account and getting involved. thanks again! Jytdog (talk) 13:13, 30 May 2015 (UTC)

Input on Wiki standard

Does anyone have input on the units for mag susceptibility? Im going to input mag susceptibility of a lot organic and inorganic compounds and Im not sure If i should put them in as cm^3/ mol or as cm^3/g. TerpeneOtto Dec 5th 2016.

The standard for engineering is the dimensionless SI susceptibility. This is also the easiest to visualize for non-experts as it tells you directly "how easily" the material is magnetized. And SI units are the standard in quantitative science, unless something else is customary in specific disciplines. From an analytical scientific point of view, the molar susceptibility is more general, since it is to some degree temerature independent and can be used to roughly estimate material mixtures. So I would always quote SI units at room temperature. 93.132.234.212 (talk) 23:25, 18 April 2017 (UTC)

P.S. I think actually mass susceptibility is better than molar susceptibility, keeping in mind mixtures and chemically undefined materials. Anyway. For the encyclopedia, still the volumetric susceptibility is better 93.132.234.212 (talk) 23:45, 18 April 2017 (UTC)

Diamagnetic vs. Paramagnetic

This page is missing a brief explanation of para vs diamagnetic compounds. All organic compounds are diamagnetic and push the magnetic field away from the compound. All diamagnetic compunds have a -X. Paramagnetic compounds have +X. This page also needs to include Xmass and Xmol. Inorganic compounds and organometallic have both para and diamagnetic compounds.

TerpeneOtto Dec 5th 2016.

Table for estimating Magnetic Susceptibility

There is an excellent table for estimating magnetic susceptibility in Concise Inorganic Chemistry (4th ed) by J.D. Lee. It contains Organic and Inorganic ions and atoms. It is far more more useful then the table on the page. I will try to put it on the page soon. TerpeneOtto (talk) 18:46, 4 February 2017 (UTC)

Well, ions and atoms is something else than compounds. The susceptibility of most pure elements is well known, whereas the one of compunds is not. Plus for the general audience of an encyclopedia, an overwiew table of different types of substances as there is now may be much more accessible than a method to calculate the susceptibility, which probably will not apply for compound materials anyway. So I would keep the table, adding something doesn't hurt. One may discuss, however, whether all the different units in the table are really necessary. If the formula for conversion is given, it's just a matter of a multiplicaiton or devision. And anyone who actually uses these values is capable of doing this. 93.132.234.212 (talk) 23:32, 18 April 2017 (UTC)

Magnetic Moment

Niels Bohr published the calculation between magnetic susceptibility and magnetic moment. Temperature is required. The equation are published in Concise Inorganic Chemistry (4th ed) by J.D. Lee. The same book also describes how a Mag Susceptibility balance works. I'm going to add these last two titles to the page soon.TerpeneOtto (talk) 19:05, 4 February 2017 (UTC)

Xm to Xg conversion Paragraph

This math is flat out wrong. Xmass and Xmol are converted by molar mass(M) not by the density of the material. There is an entire incorrect section. This page desperatly needs one of those tags on top with the worst rating possible. TerpeneOtto (talk) 19:05, 4 February 2017 (UTC)

This article was definitely worked on by somebody with a point to push, and made extremely technical. If you understand the subject matter and could work this into an encyclopedia article that has sections that are accessible, and that is accurate in the technical parts, that would be amazing. Jytdog (talk) 01:39, 5 February 2017 (UTC)

"Frequency domain susceptibility"

Who wrote that part? I would delete it. It doesn't cite any sources except for that direct link, and if correct at all it's rather specific. As a physicist who ventures from time to time also into materials research I still couldn't really follow it and I have the suspicion the person who wrote it couldn't either. If noone complains, I would delete it. Otherwise please improve it and correct me if I'm wrong. 93.132.234.212 (talk) 23:45, 18 April 2017 (UTC)

Thank you note

This is for novices one of the most clear and elucidating articles I have found in Wikipedia on the subject, and one that for once doesn't include a zillion vectors. I don't know if I am violating policy by not suggesting specific improvements (anyone can edit or delete the comment if they think so), but I wanted to say thanks to the authors and hope no one will subtract information from it.2A02:587:4508:2C00:688F:C34C:D0FC:9449 (talk) 20:29, 25 July 2017 (UTC)