Hajo Frerichs

Quantum Design (Germany)

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Wolfgang Tremel

Johannes Gutenberg University Mainz

Martin Panthöfer

Johannes Gutenberg University Mainz

E.W. Kreutz

Fraunhofer Institute for Laser Technology

S. Kalbitzer

AM Technology (United Kingdom)

Felix Pfitzner

Johannes Gutenberg University Mainz

Muhammad Nawaz Tahir

King Fahd University of Petroleum and Minerals

Karoline Herget

Johannes Gutenberg University Mainz

Marion Wolff

Quantum Design (Germany)

D.A. Wesner

Fraunhofer Institute for Laser Technology

Sebastian Seibert

Quantum Design (Germany)

Cooperative Institutions

Johannes Gutenberg University Mainz

University of Applied Sciences Mainz

Quantum Design (United States)

Max Planck Society

King Saud University

Max Planck Institute for Polymer Research

Graz University of Technology

RWTH Aachen University

Division of Chemistry

Austrian Centre for Electron Microscopy and Nanoanalysis

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A Highly Integrated AFM-SEM Correlative Analysis Platform

Microscopy Today (2023)

Afshin Alipour Kerim Arat Hamed Alemansour L. Montès Joseph Gardiner

Abstract We describe the first truly correlative atomic force microscopy-scanning electron microscopy (AFM-SEM) platform designed from first principles and from the ground up for the study of sample properties under a wide range of magnifications. Combining these two microscopy techniques, “in situ,” into a highly integrated workstation opens unprecedented measurement capabilities at the nanoscale, while simplifying experiment workflows to yield a higher level of data throughput. Unlike SEM, the AFM offers true three-dimensional topography images, something SEM can only provide indirectly. This allows for the characterization of nano-mechanical properties, as well as for magnetic and electrical characterization of samples, which are increasingly of interest in material science, multi-component technologies (that is, solar cell and battery research), and pharmaceutical investigations. On the other hand, the SEM’s wide field-of-view is critical in identifying regions of interest with feature sizes of less than a micron, which are notoriously difficult to find over large spatial scales in conventional AFM systems. In addition, the SEM’s ability to visualize the AFM tip facilitates its navigation to aid the characterization of samples with challenging three-dimensional topographies. In this paper, we describe the major elements of the system design and demonstrate how correlative microscopy can help the characterization of samples with challenging morphologies such as the edge of a razor blade or the nanomechanical analysis of platinum nanopillars.

Characterization

Correlative

Nanopillar

10.1093/mictod/qaad083

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Citations (4)

3D Nanoprinting of All-Metal Nanoprobes for Electric AFM Modes

Nanomaterials (2022)

Lukas Matthias Seewald Jürgen Sattelkow Michele Brugger‐Hatzl Gerald Kothleitner Hajo Frerichs

3D nanoprinting via focused electron beam induced deposition (FEBID) is applied for fabrication of all-metal nanoprobes for atomic force microscopy (AFM)-based electrical operation modes. The 3D tip concept is based on a hollow-cone (HC) design, with all-metal material properties and apex radii in the sub-10 nm regime to allow for high-resolution imaging during morphological imaging, conductive AFM (CAFM) and electrostatic force microscopy (EFM). The study starts with design aspects to motivate the proposed HC architecture, followed by detailed fabrication characterization to identify and optimize FEBID process parameters. To arrive at desired material properties, e-beam assisted purification in low-pressure water atmospheres was applied at room temperature, which enabled the removal of carbon impurities from as-deposited structures. The microstructure of final HCs was analyzed via scanning transmission electron microscopy—high-angle annular dark field (STEM-HAADF), whereas electrical and mechanical properties were investigated in situ using micromanipulators. Finally, AFM/EFM/CAFM measurements were performed in comparison to non-functional, high-resolution tips and commercially available electric probes. In essence, we demonstrate that the proposed all-metal HCs provide the resolution capabilities of the former, with the electric conductivity of the latter onboard, combining both assets in one design.

Characterization

10.3390/nano12244477

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Citations (10)

Mixed Ligand Shell Formation upon Catechol Ligand Adsorption on Hydrophobic TiO₂ Nanoparticles

Langmuir (2019)

Eugen Schechtel René Dören Hajo Frerichs Martin Panthöfer Mihail Mondeshki

Modifying the surfaces of metal oxide nanoparticles (NPs) with monolayers of ligands provides a simple and direct method to generate multifunctional coatings by altering their surface properties. This works best if the composition of the monolayers can be controlled. Mussel-inspired, noninnocent catecholates stand out from other ligands like carboxylates and amines because they are redox-active and allow for highly efficient surface binding and enhanced electron transfer to the surface. However, a comprehensive understanding of their surface chemistry, including surface coverage and displacement of the native ligand, is still lacking. Here, we unravel the displacement of oleate (OA) ligands on hydrophobic, OA-stabilized TiO2 NPs by catecholate ligands using a combination of one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy techniques. Conclusive pictures of the ligand shells before and after surface modification with catecholate were obtained by 1H and 13C NMR spectroscopy (the 13C chemical shift being more sensitive and with a broader range). The data could be explained using a Langmuir-type approach. Gradual formation of a mixed ligand shell was observed, and the surface processes of catecholate adsorption and OA desorption were quantified. Contrary to the prevailing view, catecholate displaces only a minor fraction (∼20%) of the native OA ligand shell. At the same time, the total ligand density more than doubled from 2.3 nm–2 at native oleate coverage to 4.8 nm–2 at maximum catecholate loading. We conclude that the catecholate ligand adsorbs preferably to unoccupied Ti surface sites rather than replacing native OA ligands. This unexpected behavior, reminiscent of the Vroman effect for protein corona formation, appears to be a fundamental feature in the widely used surface modification of hydrophobic metal oxide NPs with catecholate ligands. Moreover, our findings show that ligand displacement on OA-capped TiO2 NPs is not suited for a full ligand shell refunctionalization because it produces only mixed ligand shells. Therefore, our results contribute to a better understanding and performance of photocatalytic applications based on catecholate ligand-sensitized TiO2 NPs.

10.1021/acs.langmuir.9b02496

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Citations (17)

Den Nachweis von Veronal

Analytical and Bioanalytical Chemistry (1907)

G. Frerichs Hajo Frerichs

10.1007/bf01304422

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A Novel Tool for Combined AFM, SEM, and Electrical Probing of Nanostructures

BIO Web of Conferences (2024)

Chris H Schwalb Hajo Frerichs Darshit Jangid Sebastian Seibert Lukas Stühn

10.1051/bioconf/202412905011

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Facile synthesis of Pd@graphene nanocomposites with enhanced catalytic activity towards Suzuki coupling reaction

Scientific Reports (2020)

Mujeeb Khan Mohammed Rafi Shaik Syed Farooq Adil Mufsir Kuniyil Muhammad Ashraf

Abstract A facile and chemical specific method to synthesize highly reduced graphene oxide (HRG) and Pd (HRG@Pd) nanocomposite is presented. The HRG surfaces are tailored with amine groups using 1-aminopyrene (1-AP) as functionalizing molecules. The aromatic rings of 1-AP sit on the basal planes of HRG through π–π interactions, leaving amino groups outwards (similar like self-assembled monolayer on 2D substrates). The amino groups provide the chemically specific binding sites to the Pd nucleation which subsequently grow into nanoparticles. HRG@Pd nanocomposite demonstrated both uniform distribution of Pd nanoparticles on HRG surface as well as excellent physical stability and dispersibility. The surface functionalization was confirmed using, ultraviolet–visible (UV–Vis), Fourier transform infra-red and Raman spectroscopy. The size and distribution of Pd nanoparticles on the HRG and crystallinity were confirmed using high-resolution transmission electron microscopy and powder X-ray diffraction and X-ray photoelectron spectroscopy. The catalytic efficiency of highly reduced graphene oxide-pyrene-palladium nanocomposite (HRG-Py-Pd) is tested towards the Suzuki coupling reactions of various aryl halides. The kinetics of the catalytic reaction (Suzuki coupling) using HRG-Py-Pd nanocomposite was monitored using gas chromatography (GC).

Suzuki reaction

Surface Modification

10.1038/s41598-020-68124-w

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Citations (40)

Processing of polymer surfaces by laser radiation

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms (1995)

E.W. Kreutz Hajo Frerichs J.N.M. Stricker D.A. Wesner

Acrylonitrile butadiene styrene

Polystyrene

Polyoxymethylene

Polypropylene

Polycarbonate

10.1016/0168-583x(95)00539-0

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Citations (27)

Analysis of Pb on Ag by Rutherford backscattering

Surface Science (1981)

Hajo Frerichs S. Kalbitzer F.J. Demond D.L. Rath D.M. Kolb

Rutherford scattering

Rutherford backscattering spectrometry

10.1016/0039-6028(81)90002-9

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Citations (11)

Guide Levels for the Decontamination of Polluted Water and Soil

Soil & environment (1993)

H. Bremer Hajo Frerichs Udo Rohweder

Human decontamination

10.1007/978-94-011-2018-0_55

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In-situ Correlative Analysis of electrical and magnetic properties of Ion-beam treated surfaces by combination of AFM and FIB

Microscopy and Microanalysis (2021)

C. Schwalb Johanna Hütner Hajo Frerichs Marion Wolff Robert Winkler

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Correlative

10.1017/s1431927621003858

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