Institute of Physics, Chemnitz University of Technology, Chemnitz, Germany.
Nanotechnology. 2010 Sep 24;21(38):385703. doi: 10.1088/0957-4484/21/38/385703. Epub 2010 Aug 27.
An approach for tailoring the magnetic properties by ion irradiation of granular perpendicular CoCrPt:SiO(2) films grown on silica particles with sizes down to 10 nm was investigated. The as-prepared samples reveal an intriguing scaling dependence of the coercive field and remnant magnetization: both parameters are found to decrease with decreasing particle size. However, Co(+) irradiation at a low fluence of 0.5 x 10(14) cm(-2) already results in an opposite scaling behavior. It is assumed that this modification is due to the enhancement of the intergranular magnetic exchange coupling of the granular CoCrPt:SiO(2) film initiated by Co(+) irradiation resulting in a modified reversal behavior. Further increase of the irradiation fluence beyond 1.6 x 10(14) ions cm(-2) leads to a degradation of the magnetic layer properties, lowering the remnant magnetization and the coercive field in the easy-axis direction. Moreover, the local magnetic properties of the samples were analyzed by magnetic force microscopy revealing magnetic multi-domain cap structures.
通过对粒径降至 10nm 的二氧化硅颗粒上生长的垂直各向异性 CoCrPt:SiO2 颗粒膜进行离子辐照，研究了一种调整其磁性能的方法。所制备的样品表现出矫顽力和剩余磁化强度的有趣的标度依赖性：这两个参数都随粒径的减小而减小。然而，Co+辐照在低通量 0.5×1014cm-2 时已经导致了相反的标度行为。据认为，这种修饰是由于 Co+辐照引发的颗粒 CoCrPt:SiO2 膜的颗粒间磁交换耦合增强，导致反转行为发生改变。在超过 1.6×1014 离子 cm-2 的辐照通量进一步增加会导致磁性层性能恶化，降低易轴方向的剩余磁化强度和矫顽力。此外，通过磁力显微镜分析了样品的局部磁性能，揭示了磁性多畴帽结构。
