Additional Imaging Modes
5
Keysight 5500 SPM User’s Guide
5-2
interaction is between single atoms in the sample and tip, giving STM
remarkably high lateral resolution.
Keysight STM tips are pre-cut or chemically etched lengths of 0.25 mm
OD, 80 % platinum - 20 % iridium wire. If the wire tip is damaged it can
be trimmed and used again. Using tips coated in insulating wax, STM
can also be performed in fluid.
The Keysight multi-purpose scanner, when equipped with an STM nose
assembly (
), can be used for STM. The nose assembly is
available with three different preamplifiers for varying sensitivity
(
Figure 7-1
STM nose assembly
A dedicated STM scanner (
) provides lower current operation
and higher resolution. The scanner is available with three preamplifier
options for varying sensitivity (see
). The color-coded preamp,
Table 3
STM nose assembly and scanner sensitivities
Color
Red
Blue
Green
Sensitivity
10 nA/V
1 nA/V
0.1 nA/V
Bandwidth
20 kHz
6.3 kHz
2 kHz
Test Resistor
100 M
1 G
10 G