Epitaxial hard magnetic SmCo5 MFM tips - a new approach to advanced magnetic force microscopy imaging.
Epitaxial hard magnetic SmCo5 MFM tips - a new approach to advanced magnetic force microscopy imaging.
复制标题
外延硬磁 SmCo5 MFM 尖端 - 先进磁力显微镜成像的新方法。
作者：
V. Neu;S. Vock;T. Sturm;L. Schultz
悬臂式扫描力传感器通过功能针尖涂层探测特定针尖-样品的相互作用，但受到涂层过程中可实现的材料性能的限制。在宽展磁力显微镜(MFM)技术的情况下，MFM针尖的磁性能，特别是对磁场和矫顽力的响应，远远落后于在合适的衬底上以优化的工艺条件制备的永磁膜的质量。我们从优化的薄膜结构入手解决了这一限制--在氧化镁(110)衬底上外延生长的高度各向异性的SmCo5薄膜--尖端被聚焦的离子束分开，并连接到悬臂梁上。在分辨率和灵敏度上不打折扣，我们展示了无与伦比的磁场刚性，这将极大地推动对具有强杂散场的磁性材料的定量微观研究，并允许在目前高达0.7T的外部磁场中进行MFM测量。针对特定样品-悬臂梁相互作用的材料优化不受衬底、薄膜结构、薄膜制备条件和针尖形状的限制，不仅限于MFM，还为其他扫描力显微镜模式提供了新的机会。
Cantilever based scanning force sensors, which probe a specific tip-sample interaction through a functional tip coating, are limited by the material performance achievable in the coating process. In case of the wide spread magnetic force microscopy (MFM) technique, the magnetic performance of MFM tips, especially the response to magnetic fields and the coercivity, fall far behind the quality known from permanent magnet films prepared with optimized process conditions on appropriate substrates. We resolve this limitation by starting from an optimized thin film architecture - a highly anisotropic SmCo5 film grown epitaxially on MgO(110) substrates - from which a tip is separated by focused ion beam and is attached to a cantilever. Not compromising on resolution and sensitivity, we demonstrate an unrivaled rigidity in magnetic fields, which will largely advance quantitative microscopic investigation of magnetic materials with strong stray fields and allows MFM measurements in external magnetic fields of currently up to 0.7 T. The material optimization for a specific sample - cantilever interaction without restrictions in substrate, film architecture, film preparation conditions and tip shape, is not limited to MFM but offers new opportunities also for other scanning force microscopy modes.