新型 AFM 原子分辨率导电探针技术研究

目的制备新型导电探针,解决目前探针针尖曲率半径较粗、饱磁力大、调频困难、不容易得到高分辨图像等问题。方法向Si探针针尖蒸镀导电金属薄膜得到导电薄膜Si探针,镀Fe薄膜厚度约为几纳米,同时保证探针的曲率半径约10 nm。利用透射电镜观察和超高真空原子力显微镜扫描镀膜前后探针Na Cl(001)表面,分析其性能。结果自制的Fe薄膜Si探针由于蒸镀了金属薄膜,探针针尖性能稳定,Si探针扫描效果的悬挂键影响被消除,同时提高了系统的扫描分辨率。结论导电薄膜Si探针能够充分利用现有的仪器设备进行实验,具有造价低、使用简单、性能稳定等优点,可以作为将来磁交换力显微镜(MEx FM)的磁性探针来测试材料的表面磁信息。

Development of a Novel Conductive Probe at Atomic Resolution in UHV-AFM

Objective To prepare a novel conductive probe to solve the existing problems such as the relatively large curvature radius of the tip of the conductive cantilever, high saturated magnetic force, low resolution and bad modulation. Methods A conductive film Si probe was obtained by evaporating of the Si probe tip with conductive metal thin film, the thickness of the Fe film was only a few nanometers, and meanwhile the curvature radius was ensured to be around 10 nm. The probe NaCl(001) surface before and after coating was observed and scanned by TEM and UHV-AFM, respectively, and the properties were analyzed. Results Because of the metal thin film evaporation, the home-built Fe thin film Si probe had a stable probe tip performance, and the hanging key effect of Si probe scanning was eliminated. At the same time, the scanning resolution of the system was elevated. Conclusion Conductive film Si probe made full use of existing equipments for experiments. It has advantages such as low cost, easy to use and stable performance. It can be used as an important tool for the magnetic exchange force measurements in spin research at atomic resolution in the future.