# What is Magnetization: Definition and 93 Discussions

In classical electromagnetism, magnetization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. Movement within this field is described by direction and is either Axial or Diametric. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. Net magnetization results from the response of a material to an external magnetic field. Paramagnetic materials have a weak induced magnetization in a magnetic field, which disappears when the magnetic field is removed. Ferromagnetic and ferrimagnetic materials have strong magnetization in a magnetic field, and can be magnetized to have magnetization in the absence of an external field, becoming a permanent magnet. Magnetization is not necessarily uniform within a material, but may vary between different points. Magnetization also describes how a material responds to an applied magnetic field as well as the way the material changes the magnetic field, and can be used to calculate the forces that result from those interactions. It can be compared to electric polarization, which is the measure of the corresponding response of a material to an electric field in electrostatics. Physicists and engineers usually define magnetization as the quantity of magnetic moment per unit volume.
It is represented by a pseudovector M.

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1. ### I Magnetization inside a diamagnetic material antiparallel to ##B_{ext}##

Let's say I have a constant magnetic field and I dive into it a diamagnetic material. Griffiths says that in the presence of a magnetic field, matter becomes magnetized and it will be found to contain many tiny dipoles with a net alignment along some direction. However, what's exactly the link...
2. ### Clarification on magnetization and temperature

Summary:: Hello, I am doing a report for my IB course that requires some mathematics to be done. I have found this thread incredibly useful and I would like to reach out to ask for some clarification. My experiment recorded the magnetic flux density directly above neodymium disc magnet, at...
3. ### Magnetization of ferromagnetic material

I have thought about the following ##\oint \vec{H}\cdot d\vec{l}=0\Leftrightarrow H_{int}(D-h)+H_{ext}h=0\Leftrightarrow (\frac{B}{\mu_0}-M)(D-h)+\frac{B}{\mu_0}h=0\Leftrightarrow M=\frac{D}{D-h}\frac{B}{\mu_0}## but (supposing what I have done is correct) I don't understand which value of ##B##...
4. ### Exploring Spin Magnetization in Non-Ideal Systems

We have a set of N spins arranged in one dimension that can take the values $$s_i=\pm 1$$. The Hamiltonian of the system is: $$H=-\frac{J}{2N}\sum_{i \neq j}^{N} s_i s_j -B\sum_{i=1}^{N}s_i.$$ where $$J>0$$, B is an external magnetic field, and the first sum runs through all the values of i and...
5. ### Lorentz force acting upon an electron moving in a circle

So as the summary suggests, I am studying Electromagnetism, magnetic properties of matter and Magnetization vector in particular. As a first example and to introduce the Magnetization vector (M), my textbook shows a ferromagnetic substance in a uniform magnetic field (B). Then, every atom of...
6. ### Confused About Where to Begin? Start Here!

I do not know where to start.
7. ### Work associated with polarization and magnetization

Hi, this is not an exercise. In some lecture notes the authors states that from elementary EM I should familiar with the fact that the work associated with polarization and magnetization of a material is given by ##\delta W = E dP## and ##\delta W = BdM##. I have to admit that I am super rusty...
8. ### Magnetic field intensity, flux density and magnetization of coax cable

Inner conductor radius = 1cm outer conductor radius = 10cm region between conductors has conductivity = 0 & 𝜇r = 100 𝜇r = 1 for inner and outer conductor Io = 1A(-az) 𝑱(𝑟) = (10^4)(𝑒^-(r/a)^2)(az) Problem has cylindrical symmetry, use cylindrical coordinate system. Find the total current...
9. ### Engineering Magnetic Field Question (saturating an iron plate)

I know that the field inside sample is a combination of the demagnetizing field and whatever applied field you may have. So these two fields together influence how big a field you need in order to magnetize the sample.
10. ### Magnetization of a Helical coil in a Reservoir of parrafin

To test an Experimental Model , my advisor said to make this investigation; I have a Reservoir of parrafin, Capacity is 50 liters, Around this Reservoir there is a Helical copper Pipe, I have to magnetize the Reservoir by using Helical coil . Many thanks For your assistance
11. ### I In NMR, Why does longitudinal magnetization decrease when....

*** Answered off site. No need for further explanation. *** I am trying to understand MR Imaging physics. In NMR, when you put some energy in a system with a static longitudinal net magnetization, you create a transverse component and the longitudinal component decreases (in other...
12. ### Statistical physics and magnetization

Homework Statement Consider a system of three aligned spins with S=1/2. There are couplings between first neighbors. Each spin has a magnetic moment ## \vec{\mu} = s \mu \vec{S}##. The system is in a field ## H= H\vec{u_z}## at thermal equilibrium. The hamiltonian is: ##H=J[S(1)S(2)+S(2)S(3)]...
13. ### Quasi-Static Magnetization of a Magnetic Substance

Homework Statement Homework Equations energy=-u_0(B)[/B] The Attempt at a Solution According to the back of the book, a. energy level separation increaess b. mean energy decreases which makes sense since B is increasing then E must be increasing negatively. c. negative (not too sure why...
14. ### Rotational dynamics of mono-domain magnetic nanoparticles

Hi, I have a question about the rotation of a single-domain magnetic nanoparticle that is suspended in a ferrofluid immersed in an external field. Specifically, I am trying to work out the path that a normal vector on the surface of the sphere traces out in time. There are 2 ways the...
15. ### Magnetization relation to magnetic field applied

A few simple questions which I am not sure about, it's about NMR. First sentence: "A magentic field B0 is applied on a sample, If the applied magnetic field B0 is stronger, the magnetisation of material is greater" . Would you say that sentence is correct? As I understood, magnetization is a...
16. ### A Relative magnetization and a Face Centered Cubic lattice

In case of simple cubic lattice relative magnetization is given by \sigma=1-\frac{1}{S}\frac{v}{(2\pi)^3}\int^{\frac{\pi}{a}}_{-\frac{\pi}{a}}\int^{\frac{\pi}{a}}_{-\frac{\pi}{a}}\int^{\frac{\pi}{a}}_{-\frac{\pi}{a}}\mbox{d} k_x\mbox{d} k_y\mbox{d}k_z(\mbox{e}^{\frac{E(\vec{k})}{kT}}-1)^{-1}...
17. ### Magnetization of the core of a long solenoid

Homework Statement A long solenoid of 60 turns/cm carries a current of 0.15 A. It wraps a steel core with relative permeability ##\mu_r=5200##. Find the magnitude of the magnetization of the core. Homework Equations ##N=\lambda L## ##\chi = \mu_r-1## ##\mu = \mu_r\mu_0##...
18. ### Hysteresis loop magnetization of Gadolinium

hello i have a few questions regarding hysteresis loop in ferromagnets as showen here . i had an experiment in which i took a piece of gadolinium and cooled it down using liquid nitrogen , than i put it in an apparatus as showen here , so i induct an oscillating magnetic field on it , forcing...
19. ### Saturation magnetization of iron as a function of temperature

Hi, I am looking for the temperature dependence of the saturation magnetization of Fe. Any help?
20. ### Stoner-Wohlfarth model, remanent magnetization

Homework Statement " Plot remanent magnetization versus the sample angle for the sample. Derive an equation for the remanent magnetization using the definition of a hysteresis loop and Stoner-Wohlfarth model. " ##H## magnetic field ##K_u## anisotropy constant ##M_s## saturation magnetization...
21. ### Finding the magnetization in nuclear magnetic resonance

Homework Statement J-coupling term between two spins is HJ = ħJ/4 σz(1) σz(2) In the measured magnetization spectrum of the spins, this leads to the splitting of the individual spin lines by frequency J, which we’ll now derive. We can write the magnetization of spin 1 as: <M1(t)> =...
22. ### Magnetic field inside and outside of a magnetized cylinder

Homework Statement An infinitely long cylinder of radius R carries a "frozen-in" magnetization, parallel to the axis, ## \vec M = ks \hat z ##. There are no free currents. Find the magnetic field inside and outside the cylinder by two different methods: (a) Locate all the bound currents and...
23. ### Just want a little hint related to magnetization

I just want to know that if Fe3+ ions are parallel to Cr3+ ions then I have found magnetization M with given data but I am just little stuck at parallel and anti parallel ions should I add magnetization for parallel ions for Total M and subtract for anti parallel ions for total M? am i going...
24. ### Isothermal magnetization

Homework Statement A magnetic salt obeys the Curie Law μoM/Bo = C/T Where M is the magnetization, Bo is the applied magnetic field in the absence of the specimen, C is a constant, and μo is the permeability of free space. The salt is magnetized isothermally from a magnetization M1 to M2. You...
25. ### Cutting magnets without losing magnetization (Curie temperature issue)

Hello, I wanted to know, if someone knows of a realistic option of, how to cut barrium ferrite magnets without using a rock saw and without demagnetizing the magnet obviously? Thanks in advance everyone.
26. ### Absolute Value of Magnetization

Hello, I'm a student of electrical engineering. This task appeared in one of the past exams. I've been using the procedure I believe should yield the correct result, however, it turns out I was wrong. Could somebody please check out where the mistake lays in my calculations? Homework Statement...
27. ### Magnetic field behind “invisible barrier”

Let us consider the following thought experiment. There is a magnetic field in free space produced by a steady current, hence solution of the (magnetostatic) Ampere's law Curl H = J. There is also a material with some parameters ε and μ and no currents, where the Ampere's law is Curl H = 0...
28. ### I What is saturation magnetization

Hi guys, I recently performed an experiment, in which I found the B-H hysteresis loops for four ferromagnetic materials. I've attached a graph of my results for one alloy in the link below, where the labels are the saturation magnetization for each driving voltage. http://imgur.com/a/2H246 My...
29. ### BH Magnetization Curve problem

Homework Statement Homework Equations Reluctance = small "L"/mu*A The Attempt at a Solution I went the route of using B/H=Mu ...since we know that B=1.2Tesla's and Mu=4pi*10^-7 we arrive at our "magnetic field intensity "H" as 954,929.7 H" BUT if I am trying to find Reluctance...
30. ### Magnetization of atom

Homework Statement We have coaxial cabel with radius R and R0=3R filled with magnetic.Magnetization J(r)=(r3-R3)/(2R3)*I/(2*pi*r).What is the magnitization if r=0(center of atom)?And what a magnetization direction of atom? Homework Equations The Attempt at a Solution I think what...
31. ### A Spin-Polarized Edge State Magnetization Biasing

Some materials, notably graphene and some other 2D nanomaterials, possesses spin-polarized edge states, e.g., where one edge may allow the conduction of spins oriented "up" while the opposite edge only allows conduction of "down" spins. My question is not why these spin-polarized states exist...
32. ### Magnetization currents of Magnets with μ_r close to 1

Neodymium-Iron-Boron magnets have a relative magnetic permeability of 1.05. According to the formula: B = μ0 * (H + M) Both the magnetizing field H and the magnetization M contribute to the magnetic field B. The magnetization M has sources and sinks, so therefore it follows from Maxwell's...
33. ### Temporary magnetization of Casimir effect plates?

Have any experiments on the Casimir effect tried what happens if the plates are temporarily magnetized when they are pulled together by the effect? E.g. measurements of what happens to passing laser beams and the like?
34. ### Volume magnetization currents - derivation confusion

Hello there, I've just been learning about surface magnetization currents circulating around hypothetical square loops. Since the magnetization is uniform the circulation currents cancel where the square loops are adjacent to one another and it can therefore be said that the current circulates...
35. ### I Difference between Zero-Field Cooling and Field Cooling

I am currently doing a experimental project work on superconductors. I am supposed to study properties of FeTeSe. I am having trouble understanding the difference between Zero-Field Cooling and Field Cooling. In both cases, I am measuring magnetization with varying temperature (from lower to...
36. ### Net magnetization with opposing magnetic fields?

Given this diagram: Two wires, having parallel and opposing current flows( Where ## I_1 = I_2 ##), creating opposing and equal magnetic fields near a ferromagnetic object(##F##), since the magnetic field of each wire is not uniform, I'm not really certain how to figure out the magnetization of...
37. ### Power XFMR magnetization currents in a "reverse" connection

If my understanding is correct, with respect to dry-type building power transformers, due to the virtues of the transformer as a dumb machine it really doesn't care which side of itself is the primary versus the secondary. In other words a 480D-208Y tranformer can be correctly connected such...
38. ### Magnetization (M) / magnetic moment (m) of NdFeB?

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...
39. ### Calculate superconductor's magnetic susceptibility from Inductance

Homework Statement Hi, I have some data taken on voltage and resistance of a coil part of a yttrium barium copper oxicde (ycbo) superconductor. I have no information about the coil itself. A thermocouple attached to the superconductor also measured the temperature of it as it was cooled. This...
40. ### Finding B, M, and H for an infinite conducting slab

Homework Statement We have an infinite slab of conducting material, parallel to the xy plane, between z = −a and z = +a, with magnetic susceptibility χm. It carries a free current with volume current density J = J0z/a in the x direction (positive for z > 0, negative for z < 0). The integrated...
41. ### Magnetic circuits and Magnetization

From my little understanding of magnetism and the magnetization process, in order to magnetize a magnet it is better to have a closed magnetic circuit. But how does an air gap affects the magnetization "strength"? Example: Assume that we have a unmagnetized horsehoe magnet with a coil around...
42. ### Finite T transverse magnetization of transverse Ising chain

Homework Statement Consider the transverse field Ising model, with $$H=-J\sum_i\left(\sigma^x_i\sigma^x_{i+1}+g\sigma^z_i\right)$$ I have to calculate the magnetization $$\langle\sigma_z\rangle$$ at finite temperature. Homework Equations The Attempt at a Solution I have to say, I'm a bit...
43. ### Finding magnetic flux density from magnetization vector

Homework Statement A long cylinder of radius a with magnetization vector M=M_0*(r/a)^2*a_φ. Find the magnetic flux density inside and outside the cylinder. Homework Equations J_m=∇×M J_ms=M×a_n[/B] A=(μ_0/4*π)*(∫(J_m/R)dv+∫(J_ms/R)ds) B=∇×A The Attempt at a Solution Basicly what I thought...
44. ### Total Magnetic Flux Density Law Problem

We know Total Magnetic Flux B = B_0 + B_m Where, B_0 is the external field and B_m is the field inside a material. Now, we get, B = B_0 + μ_0*M (M is the magnetization) My question is - Do I always have to use μ_0 ? If yes then Why? The material isn't free space, is it? & also B =...
45. ### A couple of simple magnetization problems

Homework Statement These are actually two problems that I'm merging into one because each of them seem to have conflicting solutions, and I want to clear this up. Consider a long cylinder (very long) extending in the z direction with a constant magnetization ##\vec{M}=M\hat{z}##. What are the...
46. ### Finding the magnetization vector and magnetic field?

Hello, I've been stuck on this question for a few hours and I hope someone can help. Here is the question: "Consider two materials bismuth and aluminum with χ m = −20 ×10−5 and χ m = 2 ×10−5, respectively. Find the magnetization vector and the magnetic field in these materials when they are...
47. ### Magnetic Susceptibility and Magnetization of Water

This thread coincides with a previous thread I posted on reddit: http://www.reddit.com/r/chemistry/comments/2g69vt/magnetohydrodynamics_internal_energy_and_system/ I'm trying to solve the following equation: U=TS-PV+HM. The problem is I'm having difficulty solving H delta M. I was told H is...
48. ### Calculating magnetic moment given magnetization

Homework Statement Consider a square slab of magnetized material with sides ##2a##, and thickness ##d##, as shown. The magnetization is not uniform: $$M = M_o cos(\frac{2πx}{ a}) \hat{z}$$ b) Calculate the total magnetic moment of this object. How would you guess the magnetic field decreases...
49. ### Metalworking and magnetization

I heard/read somewhere some time ago during my electromagnetism course that when rolling a piece of metal into a metal plate, the magnetization properties will vary depending on how you apply the outer magnetic field. For instance if you apply a magnetic field perpendicular to the "direction"...
50. ### Magnetization density

Can a magnetization density that is compactly supported be the gradient of a scalar field? This question relates to magnetic resonance imaging where the signal depends upon the curl of the magnetization density.