Depinning Field at Notches of Ferromagnetic Nanowires With Perpendicular Magnetic Anisotropy

作者：Kim Kab Jin; Gim Gi Hong; Lee Jae Chul; Ahn Sung Min; Lee Kang Soo; Cho Young Jin; Lee Chang Won; Seo Sunae; Shin Kyung Ho; Choe Sug Bong^*

来源：IEEE Transactions on Magnetics, 2009, 45(10): 4056-4058.

DOI：10.1109/TMAG.2009.2024893

• Activation volume
• depinning field
• gap distance
• notch
• perpendicular magnetic anisotropy

In this paper, we experimentally characterize the domain-wall depinning mechanism at notches of ferromagnetic nanowires with perpendicular magnetic anisotropy. A time-resolved magneto-optical Kerr effect detection reveals that the depinning time is exponentially proportional to the strength of external magnetic field. From an analysis based on Neel-Brown theory, the depinning field and the activation volume are quantitatively determined for several notches with different gap distances. Interestingly, both the depinning field and the activation volume are proportional to the inverse of the gap distance. This is explained by the sizeable extrinsic effect from geometric constrictions in contrast to the intrinsic properties of the films.

• 出版日期2009-10