scholarly journals Theoretical study of the frequency shift in bimodal FM-AFM by fractional calculus

2012 ◽  
Vol 3 ◽  
pp. 198-206 ◽  
Author(s):  
Elena T Herruzo ◽  
Ricardo Garcia
Keyword(s):  
Fractional Calculus ◽  
Frequency Shift ◽  
Interaction Force ◽  
Simultaneous Recording ◽  
Force Microscopy ◽  
Simultaneous Excitation ◽  
Lennard Jones ◽  
Atomic Force ◽  
Different Types ◽  
Microscopy Method

Bimodal atomic force microscopy is a force-microscopy method that requires the simultaneous excitation of two eigenmodes of the cantilever. This method enables the simultaneous recording of several material properties and, at the same time, it also increases the sensitivity of the microscope. Here we apply fractional calculus to express the frequency shift of the second eigenmode in terms of the fractional derivative of the interaction force. We show that this approximation is valid for situations in which the amplitude of the first mode is larger than the length of scale of the force, corresponding to the most common experimental case. We also show that this approximation is valid for very different types of tip–surface forces such as the Lennard-Jones and Derjaguin–Muller–Toporov forces.

scholarly journals Frequency-modulated atomic force microscopy operation by imaging at the frequency shift minimum: The dip-df mode

2014 ◽  
Vol 85 (4) ◽  
pp. 043707 ◽  
Author(s):  
Sebastian Rode ◽  
Martin Schreiber ◽  
Angelika Kühnle ◽  
Philipp Rahe
Keyword(s):  
Atomic Force Microscopy ◽  
Frequency Shift ◽  
Force Microscopy ◽  
Atomic Force

Effect of Surface Chemistry on Ruthenium Wet Etching

2021 ◽  
Vol 314 ◽  
pp. 302-306
Author(s):  
Quoc Toan Le ◽  
E. Kesters ◽  
M. Doms ◽  
Efrain Altamirano Sánchez
Keyword(s):  
Surface Roughness ◽  
Photoelectron Spectroscopy ◽  
Etching Rate ◽  
Wet Etching ◽  
X Ray ◽  
Force Microscopy ◽  
Metal Free ◽  
Atomic Force ◽  
Different Types ◽  
Effect Of Surface

Different types of ALD Ru films, including as-deposited, annealed Ru, without and with a subsequent CMP step, were used for wet etching study. With respect to the as-deposited Ru, the etching rate of the annealed Ru film in metal-free chemical mixtures (pH = 7-9) was found to decrease substantially. X-ray photoelectron spectroscopy characterization indicated that this behavior could be explained by the presence of the formation of RuOx (x = 2,3) caused by the anneal. A short CMP step applied to the annealed Ru wafer removed the surface RuOx, at least partially, resulting in a significant increase of the etching rate. The change in surface roughness was quantified using atomic force microscopy.

scholarly journals Measurement of electrostatic tip–sample interactions by time-domain Kelvin probe force microscopy

2020 ◽  
Vol 11 ◽  
pp. 911-921
Author(s):  
Christian Ritz ◽  
Tino Wagner ◽  
Andreas Stemmer
Keyword(s):  
Frequency Shift ◽  
Surface Potential ◽  
Electrostatic Force ◽  
Kelvin Probe Force Microscopy ◽  
Kelvin Probe ◽  
Force Microscopy ◽  
Atomic Force ◽  
Alternative Approach ◽  
Dc Component ◽  
Lock In

Kelvin probe force microscopy is a scanning probe technique used to quantify the local electrostatic potential of a surface. In common implementations, the bias voltage between the tip and the sample is modulated. The resulting electrostatic force or force gradient is detected via lock-in techniques and canceled by adjusting the dc component of the tip–sample bias. This allows for an electrostatic characterization and simultaneously minimizes the electrostatic influence onto the topography measurement. However, a static contribution due to the bias modulation itself remains uncompensated, which can induce topographic height errors. Here, we demonstrate an alternative approach to find the surface potential without lock-in detection. Our method operates directly on the frequency-shift signal measured in frequency-modulated atomic force microscopy and continuously estimates the electrostatic influence due to the applied voltage modulation. This results in a continuous measurement of the local surface potential, the capacitance gradient, and the frequency shift induced by surface topography. In contrast to conventional techniques, the detection of the topography-induced frequency shift enables the compensation of all electrostatic influences, including the component arising from the bias modulation. This constitutes an important improvement over conventional techniques and paves the way for more reliable and accurate measurements of electrostatics and topography.

Block Copolymer Microdomain Morphologies by Phase Detection Imaging

1996 ◽  
Vol 461 ◽  
Author(s):  
Ph. Leclère ◽  
J. M. Yu ◽  
R. Lazzaroni ◽  
Ph. Dubois ◽  
R. JéRôme ◽  
...  
Keyword(s):  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Phase Detection ◽  
Surface Phase ◽  
Force Microscopy ◽  
Microscopy Technique ◽  
Atomic Force ◽  
Different Types ◽  
Microdomain Structure ◽  
Thermodynamic Processes

ABSTRACTAtomic Force Microscopy with Phase Detection Imaging is used to study the surface microdomain morphology of thick (i.e., ca. 2 mm) films of triblock copolymers, such as polymethylmethacrylate - block - polybutadiene - block - polymethylmethacrylate copolymers prepared by a well-taylored two-step sequential copolymerization promoted by a 1,3-diisopropenylbenzene based difunctional anionie initiator. By means of this new scanning probe microscopy technique, it is shown that the surface exhibits a segregated microphase structure, corresponding to the different types of components predicted theoretically by thermodynamic processes. We investigate the relationships between the size and characteristics of the microdomain structure as a function of the molecular parameters of the constituent polymers. Our data illustrate the interest of Phase Detection Imaging in the elucidation of surface phase separation in block copolymers.

scholarly journals High-speed dynamic-mode atomic force microscopy imaging of polymers: an adaptive multiloop-mode approach

2017 ◽  
Vol 8 ◽  
pp. 1563-1570 ◽  
Author(s):  
Juan Ren ◽  
Qingze Zou
Keyword(s):  
Atomic Force Microscopy ◽  
High Speed ◽  
Interaction Force ◽  
Dynamic Mode ◽  
Microscopy Imaging ◽  
Force Microscopy ◽  
Atomic Force ◽  
Atomic Force Microscopy Imaging ◽  
Mode Tm ◽  
Mode Atomic Force Microscopy

Adaptive multiloop-mode (AMLM) imaging to substantially increase (over an order of magnitude) the speed of tapping-mode (TM) imaging is tested and evaluated through imaging three largely different heterogeneous polymer samples in experiments. It has been demonstrated that AMLM imaging, through the combination of a suite of advanced control techniques, is promising to achieve high-speed dynamic-mode atomic force microscopy imaging. The performance, usability, and robustness of the AMLM in various imaging applications, however, is yet to be assessed. In this work, three benchmark polymer samples, including a PS–LDPE sample, an SBS sample, and a Celgard sample, differing in feature size and stiffness of two orders of magnitude, are imaged using the AMLM technique at high-speeds of 25 Hz and 20 Hz, respectively. The comparison of the images obtained to those obtained by using TM imaging at scan rates of 1 Hz and 2 Hz showed that the quality of the 25 Hz and 20 Hz AMLM imaging is at the same level of that of the 1 Hz TM imaging, while the tip–sample interaction force is substantially smaller than that of the 2 Hz TM imaging.

The Identification of the Mineralogical Composition of Converter Slags on the Basis of Testing and Diagnostics

2020 ◽  
Vol 989 ◽  
pp. 248-253
Author(s):  
Margarita A. Goncharova ◽  
Irina A. Tkacheva ◽  
Maxim G. Zagorulko
Keyword(s):  
Converter Slag ◽  
Mineralogical Composition ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Technogenic Waste ◽  
Slag Structure ◽  
Metallurgical Slags ◽  
New Construction ◽  
Microscopy Method

The paper describes a methodological system of testing and diagnosing technogenic waste to create new construction composites. The converter slag structure is shown both in the form of lump materials and on the nanoscale. The results of determining the mineralogical composition of converter slags are also presented. Petrographic research of slags and their X-ray diffraction analysis are conducted with the results shown. Special attention is paid to the atomic force microscopy method. It shows that the composing minerals have unique features of the surface topography with the indication of averaged statistical data of characteristics. In further research, this experience can significantly ease the task of determining the bi-calcium silicate in the structure of other types of metallurgical slags. The information about the morphological features of the structure of various minerals will help to use this method as independent in determining the mineralogical composition of the observed materials.

scholarly journals Influence of spurious resonances on the interaction force in dynamic AFM

2015 ◽  
Vol 6 ◽  
pp. 420-427 ◽  
Author(s):  
Luca Costa ◽  
Mario S Rodrigues
Keyword(s):  
Calibration Method ◽  
Interaction Force ◽  
Measured Signal ◽  
Acoustic Excitation ◽  
Cantilever Deflection ◽  
Force Microscopy ◽  
Atomic Force ◽  
Excitation Force ◽  
Tip Position ◽  
Effective Excitation

The quantification of the tip–sample interaction in amplitude modulation atomic force microscopy is challenging, especially when measuring in liquid media. Here, we derive formulas for the tip–sample interactions and investigate the effect of spurious resonances on the measured interaction. Highlighting the differences between measuring directly the tip position or the cantilever deflection, and considering both direct and acoustic excitation, we show that the cantilever behavior is insensitive to spurious resonances as long as the measured signal corresponds to the tip position, or if the excitation force is correctly considered. Since the effective excitation force may depend on the presence of such spurious resonances, only the case in which the frequency is kept constant during the measurement is considered. Finally, we show the advantages that result from the use of a calibration method based on the acquisition of approach–retract curves.

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