Ramp scanning acquisition

Waves I and II in Figure 2.81(b) are due to the formation of Cu(I) and Cu(II) surface oxides. Subsequent reduction of these films occurs during the cathodic sweep to give waves III and IV. The points A to D represent the potentials at which reflectivity data were collected during the voltammetric scan. The potential was ramped at lOmV/s until one of these potentials was reached, at which the scan was stopped for the duration of the data acquisition. The spectrum collected at A represents the condition of the electrode surface... 

The AFM tip is engaged with zero scan size. Following the acquisition of f-d curves and the calibration of the sensitivity of the optical detection system, FV scans (500 x 500 nm) are recorded at a z ramp rate of > a few Hz. The maximum load applied to the samples should be limited to 12 nN. 

The nanotribological properties of PLL-g-dex copolymers were characterized by the acquisition of friction-vs-load plots in a number of areas on each sample. Briefly, the sample was laterally scaimed relative to a fixed tip-cantilever assembly posilion in a line-scan mode while the sample was simullaneously ramped up and Ihen ramped down in vertical direction to provide a variation in normal load. Both normal and lateral defiection of the tip—cantilever assembly generated from the interaction between the probe tip and the sample surface were detected by a four-quadrant photodiode and interpreted as the normal load (converted based on the manufacturers normal spring constant value, = 0.58 N m ) and the frictional forces (raw photodiode signals), respectively. With the fiictionforces plotted as a function of normal load, friction-vs-load plots were obtained. To ensure a valid comparison of the frictional properties... 

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