Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Series

Physics Faculty Publications and Presentations

Atomic force microscopy

Articles 1 - 8 of 8

Full-Text Articles in Physics

Combining Atomic Force Microscopy And Shear-Force Acoustic Near-Field Microscopy To Characterize Confined Mesoscopic Fluids, Monte Allen Kozell, Theodore Brockman, Andres H. La Rosa Dec 2018

Combining Atomic Force Microscopy And Shear-Force Acoustic Near-Field Microscopy To Characterize Confined Mesoscopic Fluids, Monte Allen Kozell, Theodore Brockman, Andres H. La Rosa

Physics Faculty Publications and Presentations

An atomic force microscopy (AFM) cantilever is integrated into to a quartz tuning fork (QTF) to probe the viscoelastic properties of mesoscopic fluid layers confined between two solid surfaces under shear. Two procedures to fabricate the AFM/QTF probe are described herein. In the first, a nano-manipulator is used to transport a commercially available afm cantilever from its chip holder to the edge of a QTF tine. In the second, an afm cantilever is fabricated at the edge of the QTF tine itself. In both cases we exploit the capabilities of a dual-beam system (focused ion beam/scanning electron microscope ...


Experimental And Sensitivity Analysis Of Dmasp Cantilever Vibration Behavior Based On Mcs Theory In The Moist Environment, M. H. Korayem, Byung I. Kim, A. H. Korayem Jul 2018

Experimental And Sensitivity Analysis Of Dmasp Cantilever Vibration Behavior Based On Mcs Theory In The Moist Environment, M. H. Korayem, Byung I. Kim, A. H. Korayem

Physics Faculty Publications and Presentations

A Micro-cantilever (MC) and a probe are two main components of the atomic force microscope (AFM). The dimensions of these components are in micro scales while their oscillation amplitude is on a nanometer scale. The present study intended to not only increase the accuracy of the simulation with regard to geometric discontinuities based on the Timoshenko Beam Model using the modified couple stress (MCS) theory but also increase the accuracy of the prediction of a system behavior by considering the effect hysteresis effect into the system vibration equations based on Bouc-Wen Model. Due to the lack of the experimental results ...


Review Article: Molecular Beam Epitaxy Of Lattice-Matched Inalas And Ingaas Layers On Inp (111)A, (111)B, And (110), Christopher D. Yerino, Baolai Liang, Diana L. Huffaker, Paul J. Simmonds, Minjoo Larry Lee Jan 2017

Review Article: Molecular Beam Epitaxy Of Lattice-Matched Inalas And Ingaas Layers On Inp (111)A, (111)B, And (110), Christopher D. Yerino, Baolai Liang, Diana L. Huffaker, Paul J. Simmonds, Minjoo Larry Lee

Physics Faculty Publications and Presentations

For more than 50 years, research into III–V compound semiconductors has focused almost exclusively on materials grown on (001)-oriented substrates. In part, this is due to the relative ease with which III–Vs can be grown on (001) surfaces. However, in recent years, a number of key technologies have emerged that could be realized, or vastly improved, by the ability to also grow high-quality III–Vs on (111)- or (110)-oriented substrates These applications include: next-generation field-effect transistors, novel quantum dots, entangled photon emitters, spintronics, topological insulators, and transition metal dichalcogenides. The first purpose of this paper is ...


Reproducible Nanostructure Fabrication Using Atomic Force Microscopy Indentation With Minimal Tip Damage, Seunghee Jeon, Bongwoo Ryu, Wonho Jhe, Zheong G. Khim, Byung I. Kim Jan 2014

Reproducible Nanostructure Fabrication Using Atomic Force Microscopy Indentation With Minimal Tip Damage, Seunghee Jeon, Bongwoo Ryu, Wonho Jhe, Zheong G. Khim, Byung I. Kim

Physics Faculty Publications and Presentations

A uniform pattern of quantum dots and nanowires were reproducibly fabricated by creating holes in a two-layer structure using atomic force microscopy (AFM) indentation, dry-etching of polymer resists, and metal deposition through the indentation holes. The two-layer structure was created by depositing a thin gold layer onto a polymethyl methacrylate (PMMA) layer on a silicon substrate. The indentation depth was set so that the AFM tip penetrated the thin gold layer without the tip contacting the silicon substrate. This two-layer indentation was used to create a pattern of holes in the thin gold layer. Then, the PMMA was exposed to ...


Optimization Of Force Sensitivity In Q-Controlled Amplitude-Modulation Atomic Force Microscopy, Jongwoo Kim, Baekman Sung, Byung I. Kim, Wonho Jhe Aug 2013

Optimization Of Force Sensitivity In Q-Controlled Amplitude-Modulation Atomic Force Microscopy, Jongwoo Kim, Baekman Sung, Byung I. Kim, Wonho Jhe

Physics Faculty Publications and Presentations

We present control of force sensitivity in Q-controlled amplitude-modulation atomic force microscopy (AM-AFM) that is based on the high-Q quartz tuning-fork. It is found that the phase noise is identical to the amplitude noise divided by oscillation amplitude in AM-AFM. In particular, we observe that while Q-control does not compromise the signal-to-noise ratio, it enhances the detection sensitivity because the minimum detectable force gradient is inversely proportional to the effective quality factor for large bandwidths, which is due to reduction of frequency noise. This work demonstrates Q-control in AM-AFM is a useful technique for enhancement of ...


Nano-Structure Formation Driven By Local Protonation Of Polymer Thin Films, Carsten Maedler, Harald Graaf, Mingdi Yan, Andres H. La Rosa Jan 2009

Nano-Structure Formation Driven By Local Protonation Of Polymer Thin Films, Carsten Maedler, Harald Graaf, Mingdi Yan, Andres H. La Rosa

Physics Faculty Publications and Presentations

We report the creation of nano-structures via Dip Pen Nanolithography by locally exploiting the mechanical response of polymer thin films to an acidic environment. Protonation of cross linked poly(4-vinylpyridine) (P4VP) leads to a swelling of the polymer. We studied this process by using an AFM tip coated with a pH 4 buffer. Protons migrate through a water meniscus between tip and sample into the polymer matrix and interact with the nitrogen of the pyridyl group forming a pyridinium cation. The increase in film thickness, which is due to Coulomb repulsion between the charged centers, was investigated using Atomic Force ...


Cantilever Based Optical Interfacial Force Microscope, Jeremy R. Bonander, Byung I. Kim Mar 2008

Cantilever Based Optical Interfacial Force Microscope, Jeremy R. Bonander, Byung I. Kim

Physics Faculty Publications and Presentations

We developed a cantilever based optical interfacial force microscopy (COIFM) that employs a microactuated silicon cantilever and optical detection method to establish the measurement of the single molecular interactions using the force feedback technique. Through the direct measurement of the COIFM force-distance curves, we have demonstrated that the COIFM is capable of unveiling structural and mechanical information on interfacial water at the single molecular level over all distances between two hydrophilic surfaces.


Direct Comparison Between Phase Locked Oscillator And Direct Resonance Oscillator In The Noncontact Atomic Force Microscopy Under Ultrahigh Vacuum, Byung I. Kim Nov 2004

Direct Comparison Between Phase Locked Oscillator And Direct Resonance Oscillator In The Noncontact Atomic Force Microscopy Under Ultrahigh Vacuum, Byung I. Kim

Physics Faculty Publications and Presentations

I have demonstrated the advantage of the phase locked oscillator (PLO) over the conventional direct resonance oscillator (DRO) in noncontact mode atomic force microscopy (AFM) under ultrahigh vacuum. Direct comparison between PLO and DRO has been made in terms of background noise level, temporal response, and stability. Compared to the DRO method without phase coherence, the experimental results show that the PLO method is more effective in reducing the noise level and enhancing the stability over all force regimes in UHV noncontact AFM. The noise reduction and stability enhancement in PLO indicate the important role of the phase coherent effect ...