SurfaceScience21 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 91: Poster Session VII: Scanning probe techniques: Method development II

O 91.6: Poster

Donnerstag, 4. März 2021, 10:30–12:30, P

Development of a Variable-Temperature High-Speed Scanning Tunneling Microscope — •Zechao Yang, Leonard Gura, Jens Hartmann, Heinz Junkes, Florian Kalass, Matthias Brinker, William Kirstaedter, Markus Heyde, and Hans-Joachim Freund — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany

To understand the crystalline to vitreous transition in oxide films as a function of temperature in real space and at real time, we developed a variable-temperature high-speed scanning tunneling microscope.

The scanner consists of two independent tube piezos for slow and fast scanning, respectively. For fast scans, we use spiral geometries to avoid image distortions. The spiral geometry and the tip velocity are adjustable.

The STM tip scans in quasi-constant height mode with a predefined tilt correction. The surface topography can then be deduced from the logarithm of the tunneling current. We implemented the scan control into the EPICS framework [1] and developed highly customizable, purely python based software for the image analysis.

With these tools, we atomically resolved diffusion processes within an O(2x2) structure on Ru(0001) with a time resolution of 25 milliseconds per frame. The measurements prove the vibrational stability and low thermal drift characteristics of our microscope.

For future high temperature measurements we will use a continuous flow cryostat to counter-cool the piezo material of the scanner.

[1] Junkes, H. et al. (2018). ICALEPCS2017, pp. 1762-1766.