一种基于惯性压电马达的扫描隧道显微镜

A Simple Scanning Tunneling Microscopy with Inertial Nanopositioner

本文描述了一款结构简单紧凑、可在强磁场和极低温条件下工作的扫描隧道显微镜(scanning tunneling microscope,STM)系统.首先利用环氧树脂胶将4个氮化硅圆球和铍铜弹簧片对称粘接在绝缘导轨上,通过挤压的方式固定位于其中心的滑杆,然后将绝缘导轨粘接固定于压电扫描管的一端.借助于滑杆的惯性,将压电扫描管的4个外电极接地,给压电扫描管的内电极施加一路脉冲电压信号即可实现中心滑杆的步进,控制扫描探针向样品的逼近.逼近完成后,通过向压电扫描管的4个外电极分别施加两路频率不同的推挽电压信号即可实现样品表面的XY扫描,通过压电扫描管的内电极对扫描探针-样品间距进行PID反馈调节控制.通过扫描Au(111)获得的清晰原子图像,验证了本STM系统的高稳定性和高精度.整个STM镜体外径尺寸只有15 mm,长度为25 mm,非常适合在极低温和强磁场等对STM尺寸有限制的极端环境中使用.

A novel simple and compact scanning tunneling microscope （STM） system is presented, which can be applied in high magnetic field and ultra-low temperature environments. First, four SiN balls and one CuBe spring were fixed onto an insulated rail symmetrically with epoxy glue. Then the central shaft was pressed by the SiN balls and CuBe spring to the insulated rail, which was fixed inside one end of the piezoelectric scanner tube （PST）. Applying one pulse voltage signal on the PST＇ s inner electrode and grounding the outer four electrodes, according to the principle of piezoelectricity and the inertial force of slider, the central shaft will be sliding a distance, which moves the tip toward or away from the sam- ple. After approaching, two independent push-pull voltages are applied on the outer four electrodes to perform XY scanning, and the inner electrode and PID feedback are adopted to tune the gap between the tip and the sample. The atomic resolution of Au （ 111 ） single crystal conforms the performance of the STM proposed. The diameter of the scanning head is about 15 mm and the length is about 25 ram, suit- able for application in high magnetic field and ultra-low temperature environments.