Molecular spin alignment having macro torque effects?

Click For Summary

Discussion Overview

The discussion revolves around the effects of aligned electron or nuclear spins in a magnetic field and whether this alignment can produce macro-scale torque, particularly in the context of a freely rotating rod. The inquiry touches on theoretical implications and physical phenomena related to magnetism and mechanics.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • Xerxes73 questions whether aligning electron or nuclear spins in a magnetic field can cause a rod, fixed at one end and allowed to rotate freely, to experience torque.
  • One participant confirms that this phenomenon is known as the Einstein - de Haas effect.
  • Another participant introduces the Barnett effect, which describes the opposite scenario where mechanical rotation of a ferromagnetic body leads to magnetization along the rotational axis.

Areas of Agreement / Disagreement

Participants provide related effects but do not express disagreement; however, the discussion remains open-ended regarding the implications of these effects on macro-scale torque.

Contextual Notes

The discussion does not delve into the specific conditions or assumptions required for the effects to manifest, nor does it explore the mathematical framework behind the phenomena mentioned.

xerxes73
Messages
10
Reaction score
0
Hello,

If a magnetic field aligns the electron or nuclear spins can that have a macro effect of causing torque? So for example if we had a rod and we fixed one end but allowed it to freely rotate and then aligned electron or nuclear spins would that cause the rod to rotate?

Thanks,
Xerxes73
 
Physics news on Phys.org
And the opposite effect is the Barnett effect, whereby mechanical rotation of a ferromagnetic body on its axis results in magnetization along the rotational axis.

http://prola.aps.org/abstract/PR/v6/i4/p239_1

Creator
 
Last edited:
Thanks! I appreciate the info. This led to some interesting reading. -Xerxes73
 

Similar threads

Graduate Spin-Orbit-Torque: Where is the damping-like Term in the pic and why?
  • · Replies 2 ·
Replies
2
Views
4K
Undergrad Effective Hamiltonian to Rotational Term Values
  • · Replies 0 ·
Replies
0
Views
3K
Undergrad What forces a magnet's field to track the rotation of the magnet?
  • · Replies 1 ·
Replies
1
Views
714
Why does a diamagnetic rod align perpendicular to a magnetic field?
  • · Replies 8 ·
Replies
8
Views
3K
Graduate How can a spin moment align parallel to an external field?
  • · Replies 11 ·
Replies
11
Views
5K
Undergrad Electron Spin vs Domain Creation in Permanent Magnets
  • · Replies 4 ·
Replies
4
Views
3K
Graduate Technical question about AMO experiment in a paper
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad Effective molecular Hamiltonian and Hund cases
  • · Replies 156 ·
6
Replies
156
Views
12K
Graduate Can we have molecular transitions that change multiplicity?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Ramsey spectroscopy and spin echoes
  • · Replies 3 ·
Replies
3
Views
3K