Abstract Interlayer magnetic coupling in an Au/Co/Mo/Co/Au system fabricated by molecular beam epitaxy was studied as a function of the thicknesses of the cobalt and molybdenum spacer layers (denoted as dCo and dMo, respectively). Magnetization processes and magnetic domain structures were investigated using magneto-optical techniques. In the investigated thickness ranges, various magnetization configurations of the Co layers were observed: (A) both perpendicular, (B) perpendicular and in-plane, and (C) both in-plane. The interlayer exchange coupling field HIEC was determined as a function of dMo. With increasing dMo, this coupling changed from antiferromagnetic with a huge coupling field of ≈0.27 T to ferromagnetic and again to antiferromagnetic. A coupling oscillation period of around 1.4 nm was deduced by comparing the experimental data with the Ruderman–Kittel–Kasuya–Yosida model. For configurations (B) and (C), oscillations of the saturation magnetic field HSAT(dMo) perpendicular to the sample plane were found. Simplified and precise analytical expressions for HSAT were proposed by considering HIEC as well as the uniaxial magnetic anisotropy of one and both magnetic layers, respectively. Magnetic ordering was numerically modeled taking into account the dependences of layer anisotropy and exchange coupling on dCo and dMo, respectively. This modeling well described the remanent magnetization map (dCo, dMo) determined using the polar Kerr effect. It is also shown that HIEC(dMo) induced magnetization reorientation from in-plane to out-of-plane or from out-of-plane to in-plane magnetization configurations and canted magnetization of the Co layers.

中文翻译：

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超薄 Au/Co/Mo/Co/Au 薄膜中层间耦合驱动的磁排序和磁化过程

摘要 研究了通过分子束外延制造的 Au/Co/Mo/Co/Au 系统中的层间磁耦合作为钴和钼间隔层（分别表示为 dCo 和 dMo）厚度的函数。使用磁光技术研究了磁化过程和磁畴结构。在研究的厚度范围内，观察到 Co 层的各种磁化配置：（A）都垂直，（B）垂直和面内，以及（C）面内。层间交换耦合场 HIEC 被确定为 dMo 的函数。随着 dMo 的增加，这种耦合从具有 ≈0.27 T 巨大耦合场的反铁磁变为铁磁，然后再次变为反铁磁。耦合振荡周期约为 1。通过将实验数据与 Ruderman-Kittel-Kasuya-Yosida 模型进行比较，推导出 4 nm。对于配置 (B) 和 (C)，发现垂直于样品平面的饱和磁场 HSAT(dMo) 的振荡。通过分别考虑 HIEC 以及一层和两层磁层的单轴磁各向异性，提出了 HSAT 的简化和精确解析表达式。考虑到层各向异性和交换耦合分别对 dCo 和 dMo 的依赖性，对磁序进行了数值模拟。这种建模很好地描述了使用极性克尔效应确定的剩磁图 (dCo, dMo)。