Isotropic Ferromagnetic Resonances Induced by Suppressed Anisotropy in Soft Magnetic Microstructures
Abstract
The miniaturization of electronic devices has brought new challenges and opportunities due to the appearance of unusual physical effects. Especially, the in-plane anisotropy introduced during the film deposition can be not beneficial for soft magnetic applications. Herein, we demonstrated the suppression of anisotropy in soft magnetic films by constructing quasi-three-dimensional soft magnetic microstructures which include a magnetic dots array in bottom layer and a magnetic antidots array in top layer. It is confirmed that the in-plane anisotropy can be suppressed by the characterization of hysteresis loops, ascribed to the formation of annular stripe domains induced by the competition between exchange energy and demagnetization energy in the dots array. The resonant frequencies of patterned microstructures increase from 1.2 GHz to 3.3 GHz with the increase of external magnetic fields from 32 Oe to 160 Oe. Thus, our results provide an insight for designing tree-dimensional devices without in-plane anisotropy.