Scanned Probe Microscopy conducting materials

Scanned probe microscopies (SPM) that are capable of measuring either current or electrical potential are promising for in situ characterization of nanoscale energy storage cells. Mass transfer, electrical conductivity, and the electrochemical activity of anode and cathode materials can be directly quantified by these techniques. Two examples of this class of SPM are scanning electrochemical microscopy (SECM) and current-sensing atomic force microscopy (CAFM), both of which are commercially available. 

The first of the scanning probe microscopies which overcame the limitation of STM in imaging of non conductive materials, however, was atomic force mi-... 

SWNTs also exhibit enhanced electronic properties, which include near ballistic transport (4,35-40). Therefore, SWNTs are investigated for a wide variety of potential apphcations, including conductive and high-strength composites, paint additives, nanoscale test tubes (41,42), hydrogen storage media (43,44), batteries (45), field emission materials (43,46-52), tips for scanning probe microscopy (53-59), transistors (60), diodes (61), and sensors (1, 2,18,40,62-72). 

The two techniques that can be called scanning probe microscopy differ in the method they use to detect interactions. In STM the tip is so close to the sample (both being electrically conducting) that it allows a current to flow by tunnel effect and the sample or tip moves to keep this current constant. In AFM the tip is placed on a cantilever whose deflection can be detected by the reflection of a laser beam appropriately focused. This allows the analysis of nonconducting materials, which makes the method more convenient to study membrane materials [38, 39]. 

The invention of scanning tunneling microscopy (STM) about three decades ago [1,2] opened a new age in which various related scanning probe microscopy (SPM) methods were developed and some of those were widely accepted as key tools for nanotechnology. Although the original STM limited its application to conductive materials, atomic force microscopy (AFM), which appeared soon after the invention of STM [3], proved applicable to various types of materials, including polymeric materials. 

This section describes a variant of SPM where condncing probes are used to measure the current-voltage (J-V) relationship and resistance (conductance) of conducting materials. Conducting probe AFM (CP-AFM) is also called conducting AFM, current-sensing AFM [11,126], or scanning resistance microscopy [127,128]. 

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