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Homework Help: Energy of a single-domain particle in a B-field

  1. Jan 2, 2009 #1
    1. The problem statement, all variables and given/known data

    As seen here, http://homes.nano.aau.dk/ld/EOM15.pdf [Broken] (last page):

    "Now a 1-domain paricle is placed in a magnetic field B in the z direction. The magnetization M of the particle points in a direction with an angle θ to the z-axis. The particle has volume V.

    2. Relevant equations



    3. The attempt at a solution

    I've solved the first part, determining the energy of a single-domain particle (no B-field) and a 2-domain particle (also no B-field). However, now that the 1-domain particle is placed in an external field the case is another.

    I've set the energy equal to:

    "magnetostatic energy" + "energy from the dipole / field interaction (-µ * B * number of magnetic dipoles * cos(theta))" + "anisotropic energy since the field is not parallel with the magnetization"

    You can see the formula attached in the gif. However, it just looks wrong to me, and I feel I've somehow forgot something very important
     

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    Last edited by a moderator: May 3, 2017
  2. jcsd
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