Miniaturized magnetostrictive strain sensors for novel applications of atomic force microscopy

基于第一个应用阶段的结果，我们将使用磁致伸缩隧道结构作为高灵敏度的应变传感器，使原子力显微镜与自感知杠杆的新应用。基于此目标，应变敏感隧穿结构的小型化将被推进到亚微米尺度，并得到微磁学模拟的支持。模拟和实验之间的比较将有助于理解的磁化反转在机械应力磁致伸缩结构，最终导致其磁化结构的控制增加。这反过来又直接影响到传感器的长期稳定性。通过有计划地开发隧道结构的层系统，我们的目标一方面是提高灵敏度和信噪比。另一方面，将在层系统中实施内部磁偏置场，以消除在最佳操作点处测量对外部偏置场的需要。为此，我们将应用传感器电极耦合到反铁磁层传感器的概念，这已经非常成功地解决了一个类似的问题与磁电磁场sensors.With这些新的自感知杠杆，我们将进行原子力显微镜实验在环境条件下，在真空中，并在不同的样品系统的液体。我们的重点是在应用中，传统的AFM的传统光学检测系统可能是有害的。此外，我们将建立和分析多个应变传感器的摩擦力和多频率测量的杠杆。

Based on the results of the first application period we will use magnetostrictive tunneling structures as highly sensitive strain sensors to enable new applications of atomic force microscopy with self-sensing cantilevers. With this aim, the miniaturization of the strain-sensitive tunneling structures will be pushed forward to submicron scales and supported by micromagnetic simulations. The comparison between simulation and experiment will contribute to the understanding of the magnetization reversal in mechanically stressed magnetostrictive structures, finally leading to an increased control of their magnetization configurations. This in turn has a direct impact on the long-term stability of the sensors.Through the planned development of the layer system of tunneling structures, we aim on the one hand on the increase of sensitivity and signal to noise ratio. On the other hand, an internal magnetic bias field will be implemented into the layer system, in order to eliminate the need for an external bias field to measure at an optimal operating point. For this purpose we will apply the concept of a sensor electrode coupled to an antiferromagnetic layer sensor, which has been very successful in solving a similar problem with magnetoelectric magnetic field sensors.With these new self-sensing cantilevers we will carry out atomic force microscopy experiments under ambient conditions, in vacuum, and in liquids on different sample systems. Our focus is on applications where conventional optical detection system of conventional AFMs can be detrimental. Furthermore, we will build and analyze cantilevers with multiple strain sensors for friction force and multi-frequency measurements.