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Search Publications by: Andrei Kolmakov (Fed)

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Displaying 1 - 25 of 41

Operando photoelectron spectromicroscopy of nanodevices: Correlating the surface chemistry and transport in SnO2 nanowire chemiresistors

June 29, 2023
Author(s)
Andrei Kolmakov, Trey Diulus, Kurt D. Benkstein, Stephen Semancik, Majid Kazemian, Matteo Amati, Maya Kiskinova, Luca Gregoratti
With size reduction of active elements in microelectronics to tens of nanometers and below, the effect of surface and interface properties on overall device performance becomes crucial. High resolution spectroscopic and imaging techniques provide a

Dependence of Single-Wall Carbon Nanotubes Alignment on the Filter Membrane Interface in Slow Vacuum Filtration

January 22, 2022
Author(s)
Jeffrey Fagan, Angela R. Hight Walker, Adam Biacchi, Andrei Kolmakov, Zia Macdermid, William D. Rice, Joshua Walker, Thomas Searles
The recent development of slow vacuum filtration (SVF) technology has shown great promise for reproducibly producing high-quality, large-area aligned films of single-wall carbon nanotubes (SWCNTs) from solution-based nanotube dispersions. In contrast to

Spatially Resolved Potential and Li-Ion Distributions Reveal Performance-Limiting Regions in Solid-State Batteries

October 19, 2021
Author(s)
Elliot Fuller, Evgheni Strelcov, Jamie Weaver, Michael Swift, Joshua Sugar, Andrei Kolmakov, Nikolai Zhitenev, Jabez J. McClelland, Yue Qi, Joseph Dura, Alec Talin
The performance of solid-state electrochemical systems is intimately tied to the potential and lithium distributions across electrolyte–electrode junctions that give rise to interface impedance. Here, we combine two operando methods, Kelvin probe force

Combining secondary ion mass spectrometry image depth profiling and single particle inductively coupled plasma mass spectrometry to investigate the uptake and biodistribution of gold nanoparticles in Caenorhabditis elegans

May 20, 2021
Author(s)
Monique Johnson, Joe Bennett, Antonio Montoro Bustos, Shannon Hanna, Andrei Kolmakov, Nicholas Sharp, Elijah Petersen, Christopher Sims, Bryant C. Nelson, Patricia Lapasset
Analytical techniques capable of determining the spatial distribution and quantity (mass and/or particle number) of engineered nanomaterials in organisms are essential for characterizing nano-bio interactions and for nanomaterial risk assessments. Here, we

Probing Electrified Liquid-Solid Interfaces with Scanning Electron Microscopy

December 2, 2020
Author(s)
Hongxuan Guo, Alexander Yulaev, Evgheni Strelcov, Alexander Tselev, Christopher M. Arble, Andras Vladar, John S. Villarrubia, Andrei Kolmakov
The mean free path of secondary electrons in aqueous solutions is on the order of a nanometer, making them a suitable probe of ultrathin electrical double layers at solid-liquid electrolyte interfaces. Employing graphene as an electron-transparent

Electron and x-ray focused beam-induced cross-linking in liquids: Toward rapid continuous 3D nanoprinting and interfacing using soft materials

September 15, 2020
Author(s)
Tanya Gupta, Evgheni Strelcov, Glenn Holland, Joshua D. Schumacher, Yang Yang, Mandy Esch, Vladimir Aksyuk, Patrick Zeller, Matteo Amati, Luca Gregoratti, Andrei Kolmakov
Additive fabrication of biocompatible 3D structures out of liquid hydrogel solutions has become pivotal technology for tissue engineering, soft robotics, biosensing, drug delivery etc. Electron and X-ray lithography are well suited to pattern nanoscopic

Extraordinary performance of semiconducting metal oxide gas sensors using dielectric excitation

May 11, 2020
Author(s)
Andrei A. Kolmakov, Radislav A. Potyrailo, Steven Go, Daniel Sexton, Xiaxi Li, Nasr Alkadi, Bruce Amm, Richard St-Pierre, Brian Scherer, Majid Nayeri, Guang Wu, Christopher Collazo-Davila, Doug Forman, Chris Calvert, Craig Mack, Philip Mcconnell
Electrical response of metal oxide semiconducting (MOS) materials to gases was discovered 70 years ago [1] and miniature low-cost MOS chemiresistors became the most popular gas sensors when chemical selectivity is not required [2, 3]. When discrimination

Radiation damage of liquid electrolyte during focused X-ray beam photoelectron spectroscopy

April 12, 2020
Author(s)
Christopher M. Arble, Hongxuan Gou, Evgheni Strelcov, Brian D. Hoskins, Patrick Zeller, Matteo Amati, Luca Gregoratti, Andrei A. Kolmakov
Ambient pressure X-ray photoelectron spectroscopy (APXPS) has become an effective tool to interrogate chemical states at surfaces relevant to real operational conditions. Herein we employ a graphene-capped microvolume array sample platform for scanning

Nanoscale mapping of the double layer potential at the graphene-electrolyte interface

January 28, 2020
Author(s)
Evgheni Strelcov, Christopher M. Arble, Hongxuan Guo, Brian D. Hoskins, Alexander Yulaev, Ivan Vlassiouk, Nikolai B. Zhitenev, Alexander Tselev, Andrei A. Kolmakov
The structure and potential drop across the electrical double layer (EDL) govern the operation of multiple electrochemical devices, determine reaction potentials and condition ion transport through the cellular membranes in living organisms. Despite more

Engineered Sulfur-MoS2-Graphene Heterostructure Cathodes for Diagnostics of Nanoscale Electrochemical Processes in High Energy Density Li-S Batteries

August 5, 2019
Author(s)
Vladimir P. Oleshko, William R. McGehee, Saya Takeuchi, Siyuan Zhang, Andrei A. Kolmakov, Jabez J. McClelland, Christopher L. Soles
Lithium-sulfur (Li-S) batteries have recently attracted enormous attention because of high theoretical specific energy (2600 Wh kg-1) and high specific capacity (1672 mAhg-1), as well as the low cost, natural abundance, and nontoxicity of elemental sulfur

In-situ near-field probe microscopy of plasma processing

December 27, 2018
Author(s)
Alexander Tselev, Jeffrey Fagan, Andrei Kolmakov
There exists a great necessity for in situ nanoscale characterization of surfaces and thin films during plasma treatments. To address this need, the current approaches rely on either ‘post mortem' sample microscopy, or in situ optical methods. The latter

In aqua electrochemistry probed by XPEEM: experimental setup, examples, and challenges

November 10, 2018
Author(s)
Slavomir Nemsak, Evgheni Strelcov, Hongxuan Guo, Brian Hoskins, Tomas Duchon, D Muller, Alexander Yulaev, Ivan Vlassiouk, Alexander Tselev, Andrei Kolmakov
Recent developments in environmental and liquid cells equipped with electron transparent graphene windows have enabled traditional surface science spectromicroscopy tools, such as XPS, PEEM, and SEM to be applied to study solid-liquid and liquid-gas

From Microparticles to Nanowires and Back: Radical Transformations in Plated Li Metal Morphology Revealed via in situ scanning electron microscopy

February 3, 2018
Author(s)
Alexander Yulaev, Vladimir P. Oleshko, Paul M. Haney, Jialin Liu, Yue Qi, Talin Alec, Leite Marina, Andrei A. Kolmakov
Li metal is the preferred anode material for all-solid-state Li batteries due to its high theoretical capacity and low voltage vs. standard hydrogen electrode. However, stable plating and stripping of Li metal in contact with a solid electrolyte at high

Low-temperature thermal reduction of graphene oxide: In situ correlative structural, thermal desorption and electrical transport measurements

January 30, 2018
Author(s)
Alexey Lipatov, Maxime Guinel, Dmitry S. Muratov, Vladislav O. Vanyushin, Peter Wilson, Andrei Kolmakov, Alexander Sinitskii
Elucidation of the structural transformations in graphene oxide (GO) upon reduction remains an active and important area of research. We report the results of in situ heating experiments, during which electrical, mass spectrometry, X-ray photoelectron

Interfacial Electrochemistry in Liquids Probed with Photoemission Electron Microscopy

December 20, 2017
Author(s)
Slavomir Nemsak, Evgheni Strelcov, Tomas Duchon, Hongxuan Guo, Johanna Hackl, Alexander Yulaev, Ivan Vlassiouk, David Mueller, Andrei Kolmakov
Studies of the electrified solid-liquid interfaces are crucial for understanding of the biological and electrochemical systems. Until recently, the use of photoemission electron microscopy (PEEM) for such purposes has been hampered by the in-compatibility

Stateful characterization of resistive switching TiO2 with electron beam induced currents

December 7, 2017
Author(s)
Brian D. Hoskins, Gina C. Adam, Evgheni Strelcov, Nikolai B. Zhitenev, Andrei A. Kolmakov, Dmitri B. Strukov, Jabez J. McClelland
Metal oxide resistive switches have become increasingly important as possible artificial synapses in next generation neuromorphic networks. Nevertheless, there is still no codified set of tools for studying fundamental properties of the devices. To this

Graphene microcapsule arrays for combinatorial electron microscopy and spectroscopy in liquids

April 27, 2017
Author(s)
Alexander Yulaev, Hongxuan Guo, Evgheni Strelcov, Lei Chen, Ivan Vlasssiouk, Andrei Kolmakov
An atomic-scale thickness, molecular impermeability, low atomic number, and mechanical strength make graphene an ideal electron transparent membrane for scanning electron microscopy and spectroscopy in liquids. Here, we present a novel sample platform made