Low Temperature, Ultra-High Vacuum STM


Pressure Tracker

Device Specifications:

Omicron ultra-high vacuum low temperature STM Setup

STM Chamber:

Lowest Temperature: 5.1 K
Cooldown from Ambient to 5.1 K: 6 hours
Time between Helium fills: ~20 hours
Z resolution: 0.005 nm
Gap Voltage: +/- .5 mV to 10 V
Tunneling Current: 2 pA to 50 nA
Pressure: down to 1x10-11 mbar

Prep Chamber:

Argon Cation Sputter Gun
Resistance Sample Heater


Figure 1: STM images showing thermal activation of thioether
rotors; dimethyl, diethyl, dibutyl and dihexyl sulfide.
Temperatures in the bottom row indicate the onset of
rotation. Tip bias = -0.3V I = 9 pA

Figure 2: Atomically resolved 3-D STM image of Pd/Cu{111} at 80 K. The Pd atoms
were deposited at a sample temperature of 1020 K, providing enough
thermal energy for the Pd atoms to bury beneath the Cu surface.
The blue depressions represent Pd impurities in a Cu{111} lattice.
Electron standing waves appear as pink waves across the surface and
around the subsurface Pd atoms. Image conditions: 0.05 V, 0.2 nA, 10 nm x 10.8 nm.

Figure 3: Atomically resolved STM image of Pd/Au{111} at 7 K.
The Pd atoms were deposited at a sample temperature of 377 K.
Pd atoms place exchange with Au atoms at the edge dislocation
of the herringbone reconstruction, alloying into the surface. The edge
dislocation appears as a bright line of atoms at the herringbone elbows,
while Pd atoms appear as depressions. Image conditions: 0.01 V, 1.3 nA.