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arXiv · 1503.00705

Measuring the magnetic moment density in patterned ultrathin ferromagnets with submicron resolution

T. Hingant·J. -P. Tetienne·L. J. Martínez·K. Garcia·D. Ravelosona·J. -F. Roch·V. Jacques
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Abstract

We present a new approach to infer the surface density of magnetic moments $I_s$ in ultrathin ferromagnetic films with perpendicular anisotropy. It relies on quantitative stray field measurements with an atomic-size magnetometer based on the nitrogen-vacancy center in diamond. The method is applied to microstructures patterned in a 1-nm-thick film of CoFeB. We report measurements of $I_s$ with a few percent uncertainty and a spatial resolution in the range of $(100$ nm)$^2$, an improvement by several orders of magnitude over existing methods. As an example of application, we measure the modifications of $I_s$ induced by local irradiation with He$^+$ ions in an ultrathin ferromagnetic wire. This method offers a new route to study variations of magnetic properties at the nanoscale.

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T. Hingant, J. -P. Tetienne, L. J. Martínez, K. Garcia, D. Ravelosona, J. -F. Roch, V. Jacques. 2015-03-02. Measuring the magnetic moment density in patterned ultrathin ferromagnets with submicron resolution. https://doi.org/10.1103/physrevapplied.4.014003

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