Magnetization (M) / magnetic moment (m) of NdFeB?

[flofelis]

Dear All,

Hi, I am pretty new in the area of magnetism. Please pardon me for some questions that might be pretty fundamental and basic here.

I am trying to understand the difference between magnetic moment and magnetization. I thought I understood magnetization as the degree to which a magnet is magnetised, thus the amount of field present within it, as in the self induced magnetic field within the magnet itself. However, I am unsure as to how the magnetization affect the external of the permanent magnet... and then I thought magnetic moment would be the moment (i.e. the torque) onto the permanent magnet giving that amount of magnetization within it, so the magnetic moment and be related somewhat to the magnetization
=S sorry, I hope I am not making this sound too confusing as I am pretty much confused myself.

I would need to clarify my doubts in this as I need to find out the magnetization for a cylindrical NdFeB for a dynamic equation that I am working on. I understand that the NdFeB, a ferromagnetic material has a non-linear B-H relationship, thus it doesn't have a constant magnetization value. Nonetheless, is there anyway I could find out? I would like to assume that the region of operation I will work on is linear as the range of current supply is small (i.e. ~ +/-5A) but I am not sure if that makes sense.

I look forward to any advice and suggestions =)
Thank you!

 

[Charles Link]

Magnetism in materials can be a rather complex subject, but I do have a couple suggestions. It sounds like you are quite new to the subject, but might already have had some E&M coursework. About a week or two ago, someone posted a question on Physics Forums in the Homework and Coursework Questions section, subsection Engineering and Computer Science Homework about the magnetic field of a ferromagnetic cylinder. (This one is a rectangular cylinder, but the equations are similar for a round cylinder.) This homework problem might be a good starting point in doing calculations with magnetic materials, because there are no external fields in this homework problem, and it also doesn't have the extra detail of the magnetic susceptibility of the material, etc. I responded to the student's homework question in detail, and I think you might find it useful. It's a good starting point. You're likely to have other questions, but this might give you a good start. (I'd give you a "link" to the PF post, but I don't know how to post the "link" back to another PF post.)

 

[flofelis]

Hi Charles,

Thanks for the suggestion =) that sounds pretty good.. I would love to have the link =) will it be alright to email it to me at flo_felis@hotmail.com?
Thanks again!

 

[Charles Link]

I should know how to share the Physics Forums post to this posting, but I don't know how to do it. I can share it to Facebook, etc..., but I also don't know how to send one of their "links" to the e-mail...It's probably very simple, but I can't figure out how. The title is "the Magnetic Field of a ferromagnetic cylinder." It should be good reading. I need to find how to share a "link" on the PF... Can you try either the "search" on this website or just scroll down to it=the posting is a homework question on March 21, 2016. I think I finally found the "link" of the posting. No doubt there is an easier way to do this: https://www.physicsforums.com/threads/magnetic-field-of-a-ferromagnetic-cylinder.863066/

 

[flofelis]

Hi Charles, thank you so much for the link! Yerp, I can see the page now =) thanks again for your help!