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1answer
32 views

Ferromagnets - Permanent?

When researching about the Curie-Temperature and magnets in general, something got me confused. What is the difference between a ferromagnet and a permanent magnet? In a ferromagnet the spins are ...
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0answers
14 views

Monte Carlo Metropolis method - trial step algorithm [migrated]

I'm working on a Magnetization simulation and writing an algorithm using the metropolis method. I am using a change in energy and a Boltzmann distribution, but, my question is about the trial step. ...
0
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1answer
31 views

Does the electromagnetic force “split” at lower than normal energies?

Since we have working models for forces "combining" or being describable via a single framework at higher energies (such as the "electroweak" force and the aim of GUTs), does electromagnetism split ...
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1answer
27 views

The magnetic moments of Hadrons

So I am very confused about how to find the magnetic moment of a arbitrary hadron. I have found out that the magnetic moment of a quark is given by: $\mu_q = \frac{e_qM_p}{m_q}\mu_N$ Where: $e_q, ...
0
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1answer
19 views

Larmor Frequency for Spin Transition

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/larmor.html Consider the process of Larmor precession of the magnetic moment associated with the spin angular momentum of an electron inside a ...
3
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1answer
34 views

Conservation of Angular Momentum in Einstein - de Haas effect

I am not really sure why the law of conservation of angular momentum should hold true in the Einstein - de Haas effect. Consider the following excerpt about the phenomenon (taken from Magnetism in ...
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2answers
30 views

Direction of torque due to magnetic moment

I have a problem with determining the direction of torque due to magnetic moment on a current loop. Since the torque is defined as $$ \tau = p_m \times B $$ so I guess the direction of the torque ...
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0answers
25 views

How do magnets break rotational symmetry?

I have heard that magnets break rotational symmetry, but I do not understand why? In context, I believe they are talking about the local magnetization vector in the material when they say a magnet ...
3
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0answers
50 views

In quantum descriptions of atoms why are observables (which we derive from the wave function) attributed to electrons?

For example the orbital angular momentum, for the hydrogen atom. Is this the total angular momentum of the atom(electron and proton) or just the electron? I am asking because, I am learning about how ...
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1answer
162 views

Earth Maybe a Compass or Not [closed]

Does the Earth magnetic pole point to something in our solar system or farther? Like the Sun.
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2answers
31 views

Permanent Magnet Lines & Currents:

A permanent magnet produces lines of magnet flux that we call a "magnetic field". Those lines come from inside the magnet, come out of the N pole, loop outside the magnet, & return back into the ...
4
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2answers
141 views

For the transition metals, how does counting the number of up-spins and down-spins still give you a non-integer magnetic moment?

The transition metals like Fe, Co and Ni have magnetic moments of 2.2, 1.7 and 0.6 Bohr magnetons, respectively. The band theory says that you get this when you calculate the density-of-states of the ...
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0answers
22 views

Is the saturation magnetization of a thin film different if you apply the field at different directions?

I'm getting different values of the saturation magnetization when I measure them in-plane versus out of plane. The saturation magnetization for the out of plane measurement is greater than in the in ...
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0answers
34 views

If I know how many atoms I have in a film, can I know the total magnetic moment?

Say I have a Co film and I know its volume so I know the total number of atoms in it. Using this plus the knowledge that each atom has a magnetic moment of 1.7 Bohr magnetons, would the total magnetic ...
3
votes
2answers
158 views

The Einstein–de Haas effect on a ferromagnetic coil which generates the external magnetic field

The Einstein–de Haas effect, if I understand it correctly, demonstrates a deep relationship between the intrinsic angular momentum (spin) and the magnetic moment of a particle; For this reason when a ...
2
votes
1answer
56 views

Applying downward force on someone without adding to their weight

I am creating a scenario for a superhero comic, and need help with an idea. I'd like the solution to be based in scientific theory, or at least scientific fantasy, as opposed to resorting to simply ...
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0answers
27 views

Dipoles in an external rotating field?

Consider a bunch of magnetic dipoles in $x-y$ plane in an external magnetic field $B(t)=B_0 \hat{z}+B_1(\cos\omega t~\hat{x}+\sin\omega t~\hat{y})$. The dipoles are rotating around $z$ axis and of ...
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0answers
15 views

Magnetic moment of a ferrimagnet of some geometry

How can I find the magnetic moment of a ferrimagnet of given geometry, particularly in terms of its remanent magnetization? That is, say you have a cylindrical magnet of known radius and height, ...
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0answers
23 views

Why is it necessary to break symmetry to get magnetoelectric effect in multiferroics?

Spatial or time symmetry needs to be broken for both magnetic and electric to happen in the same material. But how is symmetry hindering the process?
0
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1answer
66 views

How would the frequency of particle spin be estimated if it really was rotation?

I understand from reading that particle spin is not real spin as the globe spins. from what I have read particle spin came about because of the magnetic field of a particle. If I understand the text ...
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1answer
57 views

How would one get the particle beam in Stern Gerlach experiment

How would I get a beam of silver atoms? I imagine this to be problematic, since the silver atoms are neutral. How would I accelerate them?
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2answers
125 views

Larmor Precession - What does precession actually means?

Larmor Precession - What does precession actually means? Is it change in the orientation of the axis with which electron revolves around the orbit or what. But, shouldn't the radius of the orbit ...
1
vote
1answer
648 views

Finding the magnetic moment of a permanent magnet to calculate the torque when exposed to a magnetic field

A permanent magnet has a magnetic moment $m$ associated with it. When exposed to a magnetic field $B$ the torque acting on the magnet can be calculated as $\tau = m \times B$. I am trying to ...
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2answers
107 views

If I double the amount of oxygen molecules, do I double the paramagnetic force?

Oxygen is well known to be paramagnetic. If I take one molecule, $O_2$, and measure its paramagnetic force due to externally applied magnetic field, and then add another molecule near the first ...
1
vote
1answer
365 views

Calculating Dipole Magnetic Moment Given Magnetic Field Strength [closed]

I am trying to figure out how to solve the following: The Earth's magnetic field can be represented, in a first approximation, by a magnetic dipole placed in the Earth's center, at least up to ...
0
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1answer
262 views

difference between magnetic dipole moment and torque on a magnetic dipole?

I am a bit confused. What is the difference between magnetic dipole moment and torque on a magnetic dipole ?
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2answers
757 views

Relation between magnetic moment and angular momentum — classic theory

How do I prove the relation between the vectors of magnetic moment $\vec\mu$ and angular momentum $\vec L$, $$\vec\mu=\gamma\vec L$$ ? Many text books and lecture notes about the principles of ...
2
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0answers
46 views

What is the volume magnetization of Fe3O4 (magnetite) monodomains at room temperature?

Magnetite is great stuff for making ferrofluids and has a huge amount of literature. Yet I can't seem to find an answer to the simple question in the title. The magnetization of various bulk ...
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1answer
258 views

Magnetic moment of an iron-core solenoid

I'm currently developing a Simulink model for the attitude control system (ACS) of an undergrad-developed CubeSat. The ACS uses magnetorquers for attitude actuation. The magnetorquers are iron-nickel ...
0
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1answer
66 views

Are the electrons spin and his magnetic dipole moment unambiguously connected?

Is the angle between the spin orientation and the magnetic dipole orientation for all electrons and under all circumstances the same?
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0answers
47 views

Feynman Parametrization in muon magnetic moment

I am calculating the muon magnetic moment due to Electroweak interactions in one loop diagrams involving $W$ bosons. While referring a particular research article by John S. Curiale, titled Weak ...
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2answers
436 views

Repelling a weak permanent magnet with an electromagnet

I have a question about magnetic repulsion. Suppose I have a permanent magnet (axially magnetized) placed on top of the iron core of an electromagnet. I want to switch on the elctromagnet to repel the ...
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0answers
63 views

How to find magnetic moment using android sensors?

I am working on android application which analyze magnetic field and should find position of magnet in predefined space. I am using for development permanent magnetic dipole and android sensors ...
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0answers
75 views

W boson one loop electroweak contribution to muon g-2

I want to calculate the one loop W boson contribution (triple gauge boson vertex WW-Photon) to the muon anomalous magnetic moment g-2 with the help of Dimensional Regularization. Diagram given below: ...
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2answers
139 views

What is the physical significance of the Curie constant?

What is the physical significance of the Curie constant? I understand it depends on the effective moment of the ion and hence must be some measure of it, but what is it exactly? Like some average ...
0
votes
1answer
237 views

Finding the vector potential of an infinite cyclinder with uniform surface current

This is the second part of a problem in Griffith's "Introduction to Electrodynamics 4th Edition" (problem 6.16). The first part was to find the magnetic field inside a coaxial cable (2 concentric ...
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3answers
2k views

How to demagnetize a magnet temporarily?

How to demagnetize a magnet temporarily? Is it possible making a permanent magnet demagnetize for a short span of time? Or at least long time but temporarily!
0
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0answers
118 views

BH Curve of NdFeB Magnet, Grade N50

Every magnet manufacturer provides his own BH-demagnetazation curve of the Neodymium Iron Boron (NdFeB) permanent magnet, grade N50, differently from other manufacturers. Is there a trusted ...
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0answers
40 views

can magnet used in engines

My friend has told an idea that if the same poled magnets are placed in the motors instead of engines,it will produce the ultimate energy.because same poles are repelling each other. is it possible?
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1answer
68 views

Does the magnetic anisotropy state only have two possible directions?

Wikipedia says "The magnetic moment of magnetically anisotropic materials will tend to align with an easy axis". Does this mean that it is completely impossible to orient the magnetic moment with any ...
2
votes
1answer
104 views

Lifetime of the magnetization of a ferromagnet

In a ferromagnetic material, there's spontaneous magnetisation, meaning in the absence of a $\mathbf{B}$ field $\mathbf{M}\neq 0.$ This means that there may be different domains in the sample where ...
1
vote
1answer
27 views

How is energy conserved in a series of magnets, progressively moving another magnet upwards?

Imagine a tall building with windows allinged one above the other, and a railway going from the bottom of the building to the top of the building (vertically), right where the windows are. Imagine ...
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0answers
256 views

Ferro and Ferri magnetism

On which factors do the magnetic susceptibility of these type of materials depend? Id assume ferromagnets in general have higher susceptibility than ferrimagnets but is this true in all cases? For ...
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2answers
268 views

Unknown magnetic moment of orthohydrogen

Conforming to present atomic physics, the two elementary particles in hydrogen atoms can have either parallel or antiparallel magnetic moments, and the energy differences between these two kinds of ...
0
votes
1answer
458 views

Why toroid has no magnetic pole?

Our teacher taught us about Gauss law of magnetism, $\phi_B=\oint_s{\small{}}\vec {B} .\vec {ds}=0$(being valid because magnetic field line form closed loop, right?) which denies the existence of ...
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3answers
2k views

What will happen to a permanent magnet if we keep the same magnetic poles of two magnets close together for a long time?

What will happen to permanent magnet's magnetic field or magnetic ability if we keep same magnetic poles of two permanent magnet for long time? Will any magnetic loss happen over the long period of ...
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2answers
2k views

Why does Earth behave like Natural Bar Magnet?

What is the reason for the Earth to behave like a bar magnet and have poles (North and South poles)?
1
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1answer
222 views

Magnetic dipole and magnetic moment

I don't quite understand the meaning of these terms. My physics book just gives the mathematical definition of magnetic moment as $\mu=Ia$, which means nothing to me. I know it has to do with torque. ...
2
votes
1answer
200 views

Total magnetic moment in an atom

I have a doubt regarding the calculation of total angular momentum of electron in an atom. Which is the right way to do it? Method 1: Total magnetic moment $$ \begin{align} \vec{\mu_J} &= ...
1
vote
1answer
202 views

How the neutron magnetic moment was measured?

How was the neutron magnetic moment measured? Was the antineutron magnetic moment measured too?