Single-pass Kelvin force microscopy and dC/dZ measurements in the intermittent contact: applications to polymer materials

• Sergei Magonov and
• John Alexander

Beilstein J. Nanotechnol. 2011, 2, 15–27, doi:10.3762/bjnano.2.2

• amplifiers (LIAs) enabling multi-frequency measurements. The MAC III has three dual phase LIAs converting the AC inputs to amplitude and phase. These digitally-controlled analog LIAs have a broad bandwidth (up to 6 MHz) that cover the operational bandwidth of the photodetector employed in the microscope. A

• directly from the photodetector (AM–AM) or from the LIA-1 (AM–FM). The latter block scheme configuration is shown in Figure 1. In the AM–FM, the electrostatic interactions are excited by an AC voltage applied to the probe at ωelec = 3–5 kHz, which is within the bandwidth of ωmech. The electrostatic

• amplitude peak at 2ωmech is recorded and it is proportional to the force gradient signal, and therefore to d2C/dZ2. In the second configuration, the third LIA is connected directly to the photodetector and in this case the detected amplitude at 2ωelec is proportional to the electrostatic force and therefore