Variation of magnetization reversal in pseudo-spin-valve elliptical rings

Abstract

We studied nanoscale elliptical ring shaped NiFe/Cu/NiFe trilayer pseudo-spin-valve structures. The magnetization reversal processes showed simultaneous-reversal single-step transition or double-step transition involving flux closure states. For various aspect ratios (short axis to long axis) and linewidths, transition between single-step and double-step magnetization reversals was measured to form a phase diagram. When the linewidth was reduced, edge roughness became important. Simulations of the magnetization reversal behavior agreed qualitatively with our results.

Direct mapping of spin wave modes of individual Ni80Fe20 nanorings

“…Previously, the static behavior of magnetic rings including circular [7,8,9], elliptical [10,11] and rectangular rings [12,13] were extensively investigated. The switching properties of ferromagnetic ring elements have also been studied via magnetoresistance (MR) measurements [14,15,16].…”

“…This flux-closure VS is especially interesting since the magnetization (M) follows the ring edges either in a clockwise or counter-clockwise direction. Previously, the static behavior of magnetic rings including circular [7][8][9], elliptical [10,11] and rectangular rings [12,13] were extensively investigated. The switching properties of ferromagnetic ring elements have also been studied via magnetoresistance (MR) measurements [14][15][16].…”

Comparative study of the ferromagnetic resonance behavior of coupled rectangular and circular Ni80Fe20rings

“…To date, there are many reports on the static behavior of magnetic rings including circular [8][9][10], elliptical [11], triangular [12,13], square [14,15], rhombic [16], rounded rectangular [17,18], and rectangular rings [19]. The effect of ring dimensions [20][21][22], shapes [19,23], inter-ring spacing [24,25], configurational anisotropy [11,26,27], and engineered defects [28,29] on static reversal of the rings have also been examined. In contrast, reports on dynamic behavior of ring elements have focused on the investigation of circular ring [30][31][32][33] and limited work on other ring shapes such as rounded rectangular [34] and triangular rings [35].…”