A High Rigidity and Precision Scanning Tunneling Microscope with Decoupled 𝑋𝑌 and 𝑍 Scans

A new scan-head structure for the scanning tunneling microscope (STM) is proposed, featuring high scan precision and rigidity.The core structure consists of a piezoelectric tube scanner of quadrant type (for𝑋𝑌scans) coaxially housed in a piezoelectric tubewith single inner and outer electrodes (for𝑍scan). They are fixed at one end (called common end). A hollow tantalum shaft iscoaxially housed in the𝑋𝑌-scan tube and they are mutually fixed at both ends. When the𝑋𝑌scanner scans, its free end will bringthe shaft to scan and the tip which is coaxially inserted in the shaft at the common end will scan a smaller area if the tip protrudesshort enough from the common end. The decoupled𝑋𝑌and𝑍scans are desired for less image distortion and the mechanicallyreduced scan range has the superiority of reducing the impact of the background electronic noise on the scanner and enhancingthe tip positioning precision. High quality atomic resolution images are also shown.