SPM and related Instruments, Equipment and Examples

A Besocke type STM

designed for low temperature, using a liquid He Cryostat in UHV, at Colorado School of Mines. See GXSM community: Group of P. Sutter

View of our (at CSM) Low Temperature Besocke STM Head

STM Head, inset left: with sample and ramp, STM in cryostat, only inner shield is shown.

UHV STM and Prep. Chamber

UHV system in forground. Left: Preperation chamber, right: STM chamber. Behind: STM electronics and GXSM control software.

Electronic Setup used by GXSM

Here, at CSM, we were using the (old) PCI32 DSP card, the WRM-Piezodrive and a selfbuild "Besocke" Switchpanel and a dedicated selfbuild current amplifier (IVC and Bias Voltage Buffer).

Besocke Switch and Piezodrive

View of the wired up Piezodrive:

Top: PCI32 AD/DA connection panel
Middle: "WRM Piezo Drive"
Bottom: "Besocke Switch Panel"

The layout of the 19" frontpanels is available in LaTeX format in the CVS, see here Gxsm/Docs/HardwareDoc/.

IVC and Bias Buffer

The IVC and Bias Buffer is directly attached to the UHV Feedthrough.

Scanning Tunneling Microscopy and Surface Science using GXSM - some Examples:

The popular Silicon (111) surface in 7x7 reconstruction

Viewed by STM in constant current mode (approx. 1nA) in UHV, positive bias.

Data was taken using an early version of GXSM in Hannover, Group of M. Horn- von Hoegen

High Orientated Pyrolytic Graphite (HOPG)

Scanned by STM in air using constant height mode monitoring the tunneling current:

Tip: cut PtIr wire
Currend: at average 1.3nA, modulation amplitude is about 100pA
Bias: 100mV
"Atom" spacing is 2.5 Angstroem
Scan size: 65Å × 65Å

Data taken at the CSM, Group of P. Sutter.

Some Silicon (100) impressions

Large scale STM image of the Si (100) surface, featuring a screw disslocation! The "scratch" on top left was the result of some "tip-improvments"...

Tip: etched tungston wire
Scan size: 1455Å × 910Å, original image size was (2989x1869 pixels)