Quantitative decoding of interactions in tunable nanomagnet arrays using first order reversal curves.
- Author(s): Gilbert, Dustin A;
- Zimanyi, Gergely T;
- Dumas, Randy K;
- Winklhofer, Michael;
- Gomez, Alicia;
- Eibagi, Nasim;
- Vicent, JL;
- Liu, Kai
- et al.
Published Web Locationhttp://www.nature.com/articles/srep04204.pdf
To develop a full understanding of interactions in nanomagnet arrays is a persistent challenge, critically impacting their technological acceptance. This paper reports the experimental, numerical and analytical investigation of interactions in arrays of Co nanoellipses using the first-order reversal curve (FORC) technique. A mean-field analysis has revealed the physical mechanisms giving rise to all of the observed features: a shift of the non-interacting FORC-ridge at the low-HC end off the local coercivity HC axis; a stretch of the FORC-ridge at the high-HC end without shifting it off the HC axis; and a formation of a tilted edge connected to the ridge at the low-HC end. Changing from flat to Gaussian coercivity distribution produces a negative feature, bends the ridge, and broadens the edge. Finally, nearest neighbor interactions segment the FORC-ridge. These results demonstrate that the FORC approach provides a comprehensive framework to qualitatively and quantitatively decode interactions in nanomagnet arrays.