Physical Sciences and Mathematics Commons^™

Vortex Phase Boundaries From Ferromagnetic Measurements In A Patterned Disc Array, Ching-Ching Tsai, J Choi, Sunglae Cho, S J. Lee, Bimal K. Sarma, C Thompson, O Chernyashevskyy, Ivan Nevirkovets, V Metlushko, K Rivkin, J B. Ketterson

Australian Institute for Innovative Materials - Papers

Using a recently developed broadband microwave measurement technique, we have studied the hysteretic appearance and disappearance with in-plane magnetic field of the uniform ferromagnetic resonance (FMR) mode of a patterned permalloy disk array. The observed features are consistent with our micromagnetic simulations (performed on an infinite array of such disk), which predict that on decreasing the magnetic field from a positively magnetized state at positive fields the array will: (i) pass continuously into a double-vortex state; (ii) followed by a discontinuous transition to a single-vortex state; and finally (iii) discontinuously into a negatively magnetized state at some negative field. The …