MFM Domain Generation
Generate the stray field from a periodic pattern of parallel magnetic stripe domains with alternating up/down magnetization. Equivalent to Gwyddion's mfm_parallel.c.
Inputs
| Name |
Type |
Required |
Description |
| field |
DATA_FIELD |
Yes |
Topography used for grid dimensions |
Outputs
| Name |
Type |
Description |
| hz |
DATA_FIELD |
z-component of the stray field (A/m) |
| dhz_dz |
DATA_FIELD |
Vertical gradient of the stray field (A/m²) |
Controls
| Name |
Type |
Default |
Description |
| height |
FLOAT |
50e-9 |
Tip-sample separation in metres |
| thickness |
FLOAT |
20e-9 |
Magnetic film thickness in metres |
| magnetization |
FLOAT |
1e6 |
Saturation magnetization in A/m |
| stripe_width_a |
FLOAT |
200e-9 |
Width of the A (+M) domain in metres |
| stripe_width_b |
FLOAT |
200e-9 |
Width of the B (-M) domain in metres |
| gap |
FLOAT |
0.0 |
Domain wall gap between stripes in metres |
Notes
- Domains alternate between A (+M, magnetization up) and B (-M, magnetization down) with an optional gap of zero magnetization between them.
- The stray field is computed via FFT of the magnetization profile using an exponential decay transfer function.
- The field is uniform along y; stripes run parallel to the y-axis.
- dHz/dz is proportional to the MFM phase signal (force gradient), making it the quantity most directly comparable to raw MFM images.
- Useful for simulating MFM calibration samples and testing MFM analysis workflows.
- Typical stripe widths range from 100 nm to several microns.
