Abstract
So far, microwave assistance effects have been investigated for several perpendicular magnetic anisotropy materials with the sample dimension of at least above submicron. In this work, we study the microwave assisted magnetization switching in nanostructured Co/Pt dots as small as 50 nm in diameter. Significant reduction of the switching field and the increase of the critical frequency for the microwave assistance effect are clearly observed with the enhancement of the radio frequency magnetic field. This switching behavior is similar to that predicted by the single macrospin calculation and is well explained using the Stoner–Wohlfarth model in the rotating frame.