He${}^{+}$ ion irradiation enables controlled post-deposition modification of layered magnetic thin film systems. The degree of the modification and its depth profile can be tuned by the irradiation dose and energy. Here we use magnetometry and magnetic force microscopy to explore the impact of gentle He${}^{+}$ ion irradiation on synthetic antiferromagnets (SAF) consisting of ferromagnetic (FM) Co/Pt multilayers with perpendicular magnetic anisotropy (PMA), which are antiferromagnetically (AF) coupled via Ru interlayers. This system shows a rich variety of magnetic domain patterns due to the strong competition of the different magnetic energies. We show that AF interlayer exchange and perpendicular interface anisotropy energy are reduced by the ion irradiation, thus resulting in multiple successive magnetic phase transitions.

中文翻译：

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通过He +离子辐照来控制垂直各向异性合成反铁磁体的能量平衡

他${}^{+}$离子辐照可实现分层磁性薄膜系统的受控沉积后改性。修饰的程度及其深度分布可以通过照射剂量和能量来调节。在这里，我们使用磁力计和磁力显微镜来探索温和的氦气的影响${}^{+}$在由具有垂直磁各向异性（PMA）的铁磁（FM）Co / Pt多层组成的合成反铁磁体（SAF）上进行离子辐照，这些反铁磁体通过Ru夹层进行反铁磁（AF）耦合。由于不同磁能的激烈竞争，该系统显示出丰富的磁畴模式。我们表明，离子辐照降低了AF层间交换和垂直界面各向异性能，从而导致了多个连续的磁相变。