Learning AFM SECM Raman

The link below introduces the reader to the advances possible when glass, the probe of choice in electrochemistry, can be combined with AFM.  Such a combination leads to transparent integration with synergistic spectral imaging methodologies such as Raman imaging of electrochemical processes and this is also described in the link below.

The link below describes Nanonics introduction of AFM functionality to glass probes with their demonstrated excellence and general acceptance in SECM.  Moreover, it shows how these glass probes allow for transparent integration of AFM/SECM into Raman.  This opens new horizons in SECM.

This paper yields new insights into next generation Li-S batteries by using the excellence of non-optically obstructing glass SECM/AFM probes for transparent integration with on-line Raman imaging.  This transparent integration of AFM/SECM with Raman is due to the geometry of the SECM probe that does not block light from above.  The sensitive detection of the Raman spectrum arises from the lack of any optical background from the lack of any laser in the feedback of the probe.  This synergistic hybrid of SECM controlled AFM with Raman was highlighted by Arava et al to effectively image on a nanoscale the deposition of conductive and non-conductive materials.  The results lead to a better understanding of Li-S battery charging and discharging mechanisms and battery failure.

The paper images catalytic currents in post surface modification graphite with Fe and N.   The authors have highlighted the special characteristics of the Nanonics system that permit them to achieve their results.  The authors note in this publication that the measurements were carried out in non-contact mode.  This allows with a Nanonics Multiview 2000 AFM a constant separation distance of 4–8 nm from the surface.  The accurate separation distance is critical to understand the nature of the electrochemical currents in close proximity to the surface.  Furthermore, the measurements were made in liquid media with a  Q factor (quality factor) of 1500.  This was possible due to the unique feedback that Nanonics provides.  Such quality factors are impossible to achieve with oft repeated AFM with laser based feedback. 

This paper employs the ability to readily switch SECM probes for nanopipette electrochemical probes.  Such a probe was used in this paper together with the advantages of tuning forks that Nanonics’ systems have perfected.  Tuning fork feedback has no jump to contact which plagues all other AFM approaches.  This is highlighted in green in the abstract of the paper.  As a result, such nanopipette electrochemistry was able to produce 3D copper pillars with smooth surface structures and few defects to produce highly conducting copper from solution in an air environment.  The pillars which have axial ratios of 100:1 used Nanonics simple user interface to for producing  defined lithographic patterns of pillars.