FMR simulation of a microwire

[Mohammad Abu Jasem]

Hi everyone,

Currently I'm trying to reproduce the FMR of a microwire using vampire. I tried so many days long, but fail to reproduce it as I am new in FMR. I am providing the figure of the setup and the paper . The figure caption is , " Experimental setup. DC (current source and voltmeter) and RF (microwave generator and power sensor) electronics are connected to the Ni36Fe64 wire using a bias tee. "

I fail to set the geometry (wire/cylinder shape), and apply the fields.

If anyone help me to reproduce the MW absorption vs applied field , it would be helpful for me.

Thank you,

A vampire user

[gabo...@gmail.com]

Figure 3.1 from T. Dion's dissertation titled "Study of High Frequency Magnetisation Dynamics in Artificial Nanomagnets Using Micromagnetic Simulation and Spin Wave Spectroscopy" [1] might be helpful:

In the figure, you can see the LLG-based simulator mumax3 [2].  In the equation (1) of the VAMPIRE article titled "Model of damping and anisotropy at elevated temperatures: application to granular FePt films" by M. Strungaru et. al., you should see that VAMPIRE is also LLG-based.  Thus, I think you could substitute muxmax3 for VAMPIRE.

An issue for VAMPIRE, though, is that it does not output an ovf file.

A good thing about the ovf file is that its file format comes from oommf.  Therefore, the data format of the file is known and available at [4].  Thus, it is potential possible for someone to write code, such as with C++ or Python, that can take the output data from VAMPIRE and convert to or generate an ovf file.

Programs such as OOMMFTools [5] or ovf2mat [6] could then be used to convert from the ovf file to a mat file for use with Matlab.

Alternatively, it looks like OOMMFTools can help convert ovf to a numpy array.  The Python FMR code examples in M. Kügle's thesis titled "Micromagnetic simulation of nanogratings as possible devices for unidirectional spin wave propagation" [7] might be of interest for that approach.

A couple past posts to this group in which you might find some other helpful FMR information are [8] and [9].

[1] https://discovery.ucl.ac.uk/id/eprint/10113905/1/Study%20of%20High%20Frequency%20Magnetisation%20Dynamics%20in%20Artificial%20Nanomagnets%20Using%20Micromagnetic%20Simulation%20and%20Spin%20Wave%20Spectroscopy%20-%20Troy%20Dion.pdf

[2] https://mumax.github.io/

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

[4] https://math.nist.gov/oommf/doc/userguide21a1/userguide/Vector_Field_File_Format_OV.html

[5] https://pypi.org/project/OOMMFTools/

[6] https://github.com/DKGH/ovf2mat

[7] https://www.wmi.badw.de/fileadmin/WMI/Publications/Kuegle_Markus_Masterarbeit_2024_web.pdf

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

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

Kind Regards,

Gavin

VAMPIRE user