The presence of multiple competing periodicities may result in a system to go through states with modulated periodicities, an example of which is the self-similar staircase-like structure called the Devil’s Staircase. Herein we report on a novel staircase structure of domain periodicity in an amorphous and centrosymmetric Fe/Gd magnetic thin film system wherein the reciprocal space wavevector Q due to the ordered stripe domains does not evolve continuously, rather exhibits a staircase structure. Resonant X-ray scattering experiments show jumps in the periodicity of the stripe domains as a function of an external magnetic field. When resolved in components, the length-scale step change along Q_x was found to be an integral multiple of a minimum step height of 7 nm, which resembles closely to the exchange length of the system. Modeling the magnetic texture in the Fe/Gd system as an achiral spin arrangement, we have been able to reproduce the steps in the magnetization using a Landau-Lifshitz spin dynamics calculation. Our results indicate that anisotropy and not the dipolar interaction is the dominant cause for the staircase pattern, thereby revealing the effect of achiral magnetism.

多个竞争周期性的存在可能会导致系统经历具有调制周期性的状态，其中一个例子是称为“魔鬼楼梯”的自相似楼梯状结构。在此，我们报告了非晶中心对称 Fe/Gd 磁性薄膜系统中磁畴周期性的新型阶梯结构，其中由于有序条带磁畴而导致的倒易空间波矢Q不会连续演化，而是呈现阶梯结构。共振 X 射线散射实验表明，条带域的周期性随外部磁场的变化而变化。_{当解析为组件时，发现沿 Q x 的}长度尺度阶跃变化是最小阶跃高度 7 nm 的整数倍，这与系统的交换长度非常相似。将 Fe/Gd 系统中的磁性纹理建模为非手性自旋排列，我们已经能够使用 Landau-Lifshitz 自旋动力学计算重现磁化步骤。我们的结果表明，各向异性而不是偶极相互作用是阶梯图案的主要原因，从而揭示了非手性磁性的影响。