An ultrahigh vacuum fast-scanning and variable temperature scanning tunneling microscope for large scale imaging

Abstract

We describe the design and performance of a fast-scanning, variable temperature scanning tunneling microscope (STM) operating from 80 to 700 K in ultrahigh vacuum (UHV), which routinely achieves large scale atomically resolved imaging of compact metallic surfaces. An efficient in-vacuum vibration isolation and cryogenic system allows for no external vibration isolation of the UHV chamber. The design of the sample holder and STM head permits imaging of the same nanometer-size area of the sample before and after sample preparation outside the STM base. Refractory metal samples are frequently annealed up to 2000 K and their cooldown time from room temperature to 80 K is 15 min. The vertical resolution of the instrument was found to be about 2 pm at room temperature. The coarse motor design allows both translation and rotation of the scanner tube. The total scanning area is about 8 x 8 microm(2). The sample temperature can be adjusted by a few tens of degrees while scanning over the same sample area.

Self-assembly of methanethiol on the reconstructed Au(111) surface

“…The STM study is performed in an UHV chamber at a base pressure of 1 ϫ 10 −10 Torr, equipped with a homebuilt variable-temperature STM. 19 The ͑111͒ surface of the monocrystalline Au sample is prepared by sputter/anneal cycles. Methanethiol gas is delivered through a variable leak valve without further purification.…”

Real-space study of the growth of magnesium on ruthenium

“…The first chamber has a commercial low-energy electron microscope (Elmitec III). The microscope can monitor growth in real time, or during heating/cooling of the substrate between 200-1600 K. The second houses a low-energy electron diffractometer and a home-made scanning tunneling microscope (STM) [9]. The STM is controlled by commercial RHK electronics and the open-source Gxsm STM software [10,11].…”

Hydrogenation and exfoliation of graphene using polyamine reagents

“…Single layer graphene was grown and investigated in an ultra-high vacuum (UHV) surface science system with base pressure below 10 -10 torr. 18 Graphene was grown onto the clean Ru(0001) single crystal surface via bulk carbon segregation to the surface. The process is driven by a decreasing C solubility with increasing Ru bulk temperature, as described by Sutter and co-workers.…”