Creation of Optimal Frequency for Electrostatic Force Microscopy Using Direct Digital Synthesizer
AbstractElectrostatic force microscopy (EFM) is a useful technique when measuring the surface electric potential of a substrate regardless of its topography. Here, we have developed a frequency detection method for alternating current (AC) bias in EFM. Instead of an internal lock-in amplifier (LIA) for EFM that only detects ωe and 2ωe, we have used other LIAs that can amplify the amplitude of specific frequency by direct digital synthesizer (DDS), that finds the optimal frequency of surface charge images. In order to confirm the performance of the proposed methods, the electrical properties of lead zirconate titanate (PZT) and triglycine sulfate (TGS) samples were measured. In addition, we compared the performances of the frequency-detection method and the conventional EFM method. Ultimately, enhanced images could be achieved using the frequency-detection method. The optimal modulated frequency-shift for force–gradient measurements was found to be 2 kHz. Additionally, we have shown that it is possible to use a hard cantilever (K = 42 N/m, 330 kHz). Therefore, we expect that this technique can be applied to measure the electrical properties of bio-molecular films. View Full-Text
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Moon, S.; Kang, M.; Kim, J.-H.; Park, K.-R.; Shin, C. Creation of Optimal Frequency for Electrostatic Force Microscopy Using Direct Digital Synthesizer. Appl. Sci. 2017, 7, 704.
Moon S, Kang M, Kim J-H, Park K-R, Shin C. Creation of Optimal Frequency for Electrostatic Force Microscopy Using Direct Digital Synthesizer. Applied Sciences. 2017; 7(7):704.Chicago/Turabian Style
Moon, Seunghyun; Kang, Mingyu; Kim, Jung-Hwan; Park, Kyeo-Reh; Shin, ChaeHo. 2017. "Creation of Optimal Frequency for Electrostatic Force Microscopy Using Direct Digital Synthesizer." Appl. Sci. 7, no. 7: 704.
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