The evolution of dynamic switching diagrams of small Permalloy ellipses with magnetic field pulse duration

Switching diagrams of a thin-film 3×1 micrometer elliptical permalloy element in a crossed-wire geometry are measured for different pulsed field durations using time-resolved scanning Kerr microscopy. “Astroid”-like diagrams were observed for pulse durations as short as 900 ps full-width half-maximum. Our study indicates an asymmetry of the switching scenarios and resulting diagrams for positive and negative hard-axis field values, stemming from misalignment of the ellipse major axis with respect to the easy axis of the deposited film. Spatially resolved scans reveal the reluctance to switching of sample edges. The results are compared to Landau-Lifshitz-Gilbert micromagnetic simulations.