How to compute the resonant frequency of the magnetic material?

[mabola safar]

Dear All,

I want to examine how the magnetic moment of the magnetic material changes with the external electromagnetic wave.

As long the frequency of the electromagnetic wave is same as the resonant frequency of the magnetic material, the electromagnetic wave should cause the spin filpping in the magnetic material.

Does VAMPIRE have the function to compte the resonant frequency of the magnetic material? If so, is there any tutorial to do this calculation?

Would anyone please give me some suggestions/comments?

Thank you in advance.

Kieran

[gabo...@gmail.com]

Section "II. FERROMAGNETIC RESONANCE USING ATOMISTIC SPIN DYNAMICS" in the VAMPIRE article at [1], or [2], describes extracting resonance frequency with a Lorentzian curve fit.

The ferromagnetic resonance (FMR) module of VAMPIRE seems not well documented.  The developers are probably still looking for people that can contribute manual entries as seen at [3].

There were a few VAMPIRE users working on FMR calculations as seen at [4] and [5].

An abstract at [6] mentions a ferromagnetic resonance frequency shift calculated by an electromagnetic field simulator based on Maxwell's equation.

A thesis at [7] contains Matlab code that might help for the fast Fourier transform (FFT), or you might be interested in a FFT Python script (fft.py) at [8].

VAMPIRE solves the Landau-Liftshitz-Gilbert (LLG) equation (13) in [9].

Even though section "2. Methods" of [10] and section "4.2. Simulate the measurement with mumax3 (optional)" [11] are for different simulators, the information given describes ferromagnetic resonance from solving the LLG equation from other perspectives.

Hope that helps.

[1] https://arxiv.org/abs/2002.02865v1

[2] https://etheses.whiterose.ac.uk/id/eprint/28970/

[3] https://groups.google.com/g/vampire-users/c/Dcb9wCMqQQc/m/GGlThr9JBwAJ

[4] https://groups.google.com/g/vampire-users/c/or3XuSr_rxI/m/rtvD1b1OAQAJ

[5] https://groups.google.com/g/vampire-users/c/-9dcWgf9eF4/m/hKyRyTY9CwAJ

[6] https://doi.org/10.1109/TMAG.2013.2247031

[7] https://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Auu%3Adiva-302889

[8] https://groups.google.com/g/vampire-users/c/s8xhDaomocY/m/lFdhiVQfBgAJ

[9] https://doi.org/10.1088/0953-8984/26/10/103202

[10] https://www.researchgate.net/publication/325434610_Bias-free_giant_tunability_of_microwave_properties_in_multilayer_rhomboid_nanomagnets

[11] http://webs.fmc.uam.es/magnetrans.group/PDFs/FMR_report.pdf

Kind Regards,

Gavin

VAMPIRE user

On Thursday, February 6, 2025 at 6:41:54 PM UTC-7 mas...@googlemail.com wrote:

Dear All,

I want to examine how the magnetic moment of the magnetic material changes with the external electromagnetic wave.

As long the frequency of the electromagnetic wave is same as the resonant frequency of the magnetic material, the electromagnetic wave should cause the spin flipping in the magnetic material.

Does VAMPIRE have the function to compute the resonant frequency of the magnetic material? If so, is there any tutorial to do this calculation?