Co/Ptナノドットにおけるマイクロ波アシスト磁化反転の交流磁場強度依存性

Abstract

Microwave-assisted magnetization switching MAS has been expected as one of the prominent future ultra-high-density magnetic recording technologies. In this paper, we have studied the radio frequency RF field dependence of the switching behavior of Co/Pt nanodot arrays with various dot diameters. While the critical frequency increases and the minimum switching field decreases with increasing the RF field, MAS behavior critically depends on the dot size. For small dots less than 130i¾źnm in diameter, the critical frequency and the minimum switching field exhibit linear variation with the RF field. On the other hand, for the larger dots dot diameter i¾ź 230i¾źnm, they exhibit not only profound MAS effect but also obvious change in the behavior at a certain RF field. These changes of MAS behaviors are explained as a consequence of the change of magnetization precession mode. On the other hand, the dispersions of MAS effect exhibit no remarkable variation on the RF field.