stripe domains

[KL K]

Hello everyone, I am currently trying to simulate the stripe domain evolution process of amorphous soft magnetic FeSiB thin film materials. However, the result of my current simulation shows that the initial magnetic moments are perpendicular to the thin film. Considering the demagnetizing field, this seems to be inconsistent with physical reality. How should I modify my code to make the initial magnetic moments point in-plane, and enable the stripe domains to continuously broaden as the external magnetic field changes? Thank you all very much! 

 

[Josh Lauzier]

Hi,

While the demag field will prefer the magnetization to be in-plane, it is in competition with the uniaxial (magnetocrystalline?) anisotropy. The uniaxial anistropy as currently set will prefer an easy axis out of plane, and it's strength ( 2*Ku1/M_s ~ 1.5T) is quite strong. Your result is showing that the uniaxial anisotropy is stronger than the shape anisotropy/demag, and so the net effect is to be out of plane.

I don't have much experience with FeSib in particular, but I would first verify that that anisotropy value (both magnitude and sign) is correct. It seems rather large for an amorphous material. Typically uniaxial anisotropy is provided by magnetocrystalline anisotropy, and your material isn't crystalline.

Best,
Josh L.

[KL K]

Thank you very much for your reply, and I have also become aware of this issue. Then, if I modify the magnetic anisotropy constant to a negative value to create an easy plane, will it be possible to adjust the direction of the initial magnetic moment to be in the plane of the thin film? Thank you again for your reply!

[Josh Lauzier]

Hi,

Yes, in that case both anisotropies will favor being in-plane, so the result should be in-plane.

Best,
Josh L.