MFM studies of interlayer exchange coupling in Co/Ru/Co films: Effect of Ru layer thickness

Antiferromagnetically coupled magnetic thin films are promising candidates for the design of new magnetic storage and logic devices. The ability to control the interlayer thickness, therefore the magnetic reversal response, of exchange-coupled magnetic layers is of paramount importance in nanotechnology, especially in magnetic sensing element design and applications. In this work, magnetic force microscopy (MFM) with improved sensitivity and high spatial resolution probes was used to obtain a more detailed view of magnetization reversal behavior and domain evolution in the indirect exchange-coupled trilayer system: Co/Ru/Co. The effect of the variable Ru interlayer thickness on the exchange coupling and thus the magnetic domain structure during the ferromagnetic (FM)/antiferromagnetic (AF) coupling transition in Co/Ru/Co films is well demonstrated. The MFM images display a distinct signature of AF coupling for the films with Ru thickness of 0.4nm. MFM has proven to be an effective tool for detecting FM/AF interlayer coupling and exploring magnetic domain structures in exchange-coupled layered thin films.

反铁磁耦合磁性薄膜是设计新型磁存储和逻辑器件的有希望的候选材料。因此，在纳米技术中，尤其是在磁传感元件设计和应用方面，能够控制交换耦合磁性层的层间厚度以及磁反转响应是至关重要的。在这项工作中，使用具有更高灵敏度和高空间分辨率探头的磁力显微镜（MFM）来更详细地观察间接交换耦合三层体系（Co/Ru/Co）中的磁化反转行为和磁畴演化。可变的Ru层间厚度对Co/Ru/Co薄膜在铁磁（FM）/反铁磁（AF）耦合转变过程中的交换耦合以及磁畴结构的影响得到了很好的证明。对于Ru厚度为0.4nm的薄膜，MFM图像显示出明显的反铁磁耦合特征。磁力显微镜已被证明是检测铁磁/反铁磁层间耦合以及探索交换耦合层状薄膜中磁畴结构的有效工具。