A review of demodulation techniques for multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2020, 11, 76–91, doi:10.3762/bjnano.11.8

• measurement noise. However, multifrequency AFM applications require an additional metric due to the large number of potentially closely spaced frequencies. For example, higher-harmonic imaging with single-frequency excitation results in small harmonic amplitudes that must be estimated in the presence of both

Lyapunov estimation for high-speed demodulation in multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert,
• Michael R. P. Ragazzon and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2018, 9, 490–498, doi:10.3762/bjnano.9.47

• harmonic imaging with amplitude and phase on both a stiff and compliant sample. Lyapunov Filter System modeling A single-frequency cantilever deflection signal is modeled as a sine wave with carrier frequency fc, time-varying amplitude A(t) and phase (t) of the form For readability, explicit dependencies

• high-speed superiority of the Lyapunov filter is well established, it is compared to the lock-in amplifier in a low-speed environment. Using an NT-MDT NTEGRA AFM, amplitude and phase higher harmonic imaging was performed with a NT-MDT NSG01 and Bruker DMASP cantilever. These cantilevers were found to

Material discrimination and mixture ratio estimation in nanocomposites via harmonic atomic force microscopy

• Weijie Zhang,
• Yuhang Chen,
• Xicheng Xia and
• Jiaru Chu

Beilstein J. Nanotechnol. 2017, 8, 2771–2780, doi:10.3762/bjnano.8.276

• different kinds of nanoparticles with almost the same shape and size. Higher harmonic imaging offers better information on the distribution and mixture of different nanoparticles as compared to other techniques, including topography and conventional tapping phase. Therefore, harmonic AFM has potential

• applications in various fields of nanoscience and nanotechnology. Keywords: atomic force microscopy; harmonic imaging; material discrimination; mixture ratio; nanocomposites; Introduction Because of its extreme importance and widespread applications, nanocomposites have received more and more attention [1

• of the sixth harmonic amplitude on the set-point, a theoretical simulation of the harmonic imaging was carried out. The cantilever dynamics in the presence of the tip–sample interaction forces can be described by [31], In Equation 2, the integer number n refers to the nth eigenmode and yn denotes the