| I(V) Spectroscopy |
|
|
| STM | |
|
In I(V) Spectroscopy (or Current Imaging Tunneling Spectroscopy, CITS) a normal topographic image is acquired at fixed Io and Vo. At each point in the image feedback loop is interrupted and the bias voltage is set to a series of voltages Vi and the tunneling current Ii is recorded. The voltage is then returned to Vo and
the feedback loop is turned back on. Each I-V spectra can be acquired
in a few milliseconds so there is no appreciable drift in the tip
position. This procedure generates a complete current image Ii(x,y) at each voltage Vi in addition to the topographic image z(x,y)|VoIo.
CITS data can be used to calculate a current difference image DIVi,Vj(x,y) where Vi and Vj bracket a particular surface state, producing an atomic resolved, real space image of a surface state. This technique, for example can be used in UHV to image filled ad-atom states or the dangling bond states for silicon reconstructions. References
Copyright © 1998-2007, NT-MDT. All rights reserved. |
|
| < Prev |
|---|
