TY - CONF A1 - Sonnenburg, Elke A1 - Sommer, Konstantin A1 - Bettge, Dirk A1 - Agudo Jácome, Leonardo T1 - Präparation, Kontrastierung und Darstellung des Gefüges von additiv gefertigtem austenitischem Stahl 316L N2 - Der weit verbreitete austenitische Stahl 316L soll auch mittels additiver Fertigung verarbeitet werden (316L-AM). Zur Entwicklung optimaler Aufbauverfahren ist ein detailliertes Verständnis des Gefüges notwendig. Das additiv aufgebaute Gefüge zeigt eine Mikrostruktur, die geprägt ist von sehr hohen Abkühlraten und gerichtetem Kornwachstum. Mittels klassischer Metallographie können die Charakteristika des Gefüges wie Körner, Subkörner und Schmelzlinien sichtbar gemacht werden. Mittels EBSD werden Kristallorientierungen ermittelt und bildhaft aufbereitet. Die Feinstruktur der Körner wird im REM in der Übersicht aufgelöst. Erst im TEM kann bei hoher Vergrößerung die Natur der Zellstruktur quantitativ ermittelt werden. T2 - Metallographie 2020 CY - Online meeting DA - 16.09.2020 KW - Präparation KW - Kontrastierung KW - Additiv gefertigter Stahl PY - 2020 AN - OPUS4-51244 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stargardt, Patrick A1 - Junge, P. A1 - Greinacher, M. A1 - Kober, D. A1 - Mieller, Björn T1 - Bulk vs thermal sprayed alumina for insulation applications: A comparison of electrical and dielectrical properties N2 - Additive manufacturing (AM) processes are opening new design possibilities for large scale electrical devices such as power generators. Conventional manufacturing methods use copper rods which are wrapped, vacuum impregnated, bend and welded. These processes are labor-intensive and time-consuming. The introduction of AM methods for manufacturing the copper conductor and electrical insulation can reduce the size of the generator head, the most complex part of the generator. In this study, the electrical and dielectrical properties of additively deposited ceramic layers are investigated and compared with the properties of conventionally fabricated bulk ceramics. The ceramic layers are thermally deposited by atmospheric plasma spraying of a commercially available alumina powder. Bulk ceramics are fabricated by dry pressing and sintering of the same powder. Microstructure and porosity were analyzed by scanning electron microscopy (SEM). Electrical and dielectrical properties such as DC resistance, dielectric strength, dielectric loss, and relative permittivity were determined according to the standards. The microstructures of sprayed and sintered alumina show significant differences with respect to grain form and porosity. The density of the bulk ceramic is lower than the density of the sprayed layer due to the coarse particle size (d50 = 33 μm). Therefore, data from dense samples of the same chemical composition but lower particle size alumina powder were used for comparison. T2 - Keramik 2022 CY - Online meeting DA - 07.03.2022 KW - High Voltage Insulation KW - Thermal Spray KW - Dielectric Spectroscopy KW - Atmospheric Plasma Spraying PY - 2022 AN - OPUS4-54446 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria A1 - Mohring, W. A1 - Hesse, René A1 - Agudo Jácome, Leonardo A1 - Stephan-Scherb, C. T1 - Early Material Damage in Equimolar CrMnFeCoNi in Mixed Oxidizing/Sulfiding Hot Gas Atmosphere N2 - The use of more and more varied fuels implies an increased list of criteria that need to be addressed when choosing a material for a combustion chamber and its supply pipes. The materials must be very resistant against corrosion, especially when the process takes place at temperatures above 500°C. In this work the influence of SO2 on the surface of the “Cantor alloy” is investigated. T2 - HEA-Symposium "Potential for industrial applications" CY - Dresden, Germany DA - 12.05.2022 KW - High entropy alloy KW - Corrosion KW - Sulfiding KW - Transmission electron microscopy PY - 2022 AN - OPUS4-55397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stargardt, Patrick A1 - Bresch, Sophie A1 - Walter, P A1 - Stargardt, Patrick A1 - Höhne, Patrick A1 - Moos, R A1 - Mieller, Björn T1 - Comparison of design concepts for ceramic oxide thermoelectric multilayer generators N2 - Multilayer thermoelectric generators are a promising perspective to the conventional π-type generators. Ceramic multilayer technology is well established for production of microelectronics and piezo-stacks. Key features of ceramic multilayer technology are full-automation, cost-effectiveness, and the co-firing of all materials in one single step. This requires similar sintering temperatures of all used materials. The development of multilayer thermoelectric generators is a subject of current research due to the advantages of this technology. One of the challenges is the compatibility of the different materials with respect to the specific design. The presented study compares three different designs of multilayer generators based on a given set of material properties. Dualleg, unileg and transverse multilayer generators are compared to conventional π-type generators., the designs are evaluated regarding the expected maximum output power and power density using analytical calculations and FEM simulations. Additionally, the complexity of the production process and material requirements are assessed and design optimizations to simplify production are discussed. Besides the theoretical aspects, unileg multilayer generator prototypes were produced by tape-casting and pressure-assisted sintering. These prototypes are compared to other multilayer generators from literature regarding the power factors of the used material system and the power density. Improvements of the power output by design optimizations are discussed T2 - 18th European Conference on Thermoelectrics CY - Barcelona, Spain DA - 13.09.2022 KW - Thermoelectric oxides KW - Thermoelectric generator design PY - 2022 AN - OPUS4-55820 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Musl, O. A1 - Falkenhagen, Jana A1 - Sumerskii, I. A1 - Sulaeva, I. A1 - Mahler, A. K. A1 - Rosenau, T. A1 - Potthast, A. T1 - Mapping the Hydrophobic Composition of Lignosulfonates with 2D HIC-SEC aq. Liquid Chromatography N2 - 2D-LC provides in-depth information on the complex composition of lignosulfonates – information hitherto inaccessible by state-of-the-art lignin analytics. Analysis of 12 industrial lignosulfonates revealed considerable differences in their composition and functional dispersity - properties that are crucial for lignosulfonate usage T2 - Sustainable Materials Research Summit 2022, S.M.A.R.T CY - Vancouver, Canada DA - 07.08.2022 KW - Lignosulfonate KW - Lignin KW - Amphiphilicity KW - Hydrophobic interaction KW - Chromatography (HIC) KW - Size-exclusion chromatography (SEC) KW - Functionality type distribution KW - Two-dimensional liquid chromatography (2D-LC) KW - Molar mass distribution PY - 2022 AN - OPUS4-55510 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miliūtė, Aistė A1 - Bustamante, Joana A1 - Mieller, Björn A1 - Stawski, Tomasz A1 - George, Janine A1 - Knoop, F. T1 - High-quality zirconium vanadate samples for negative thermal expansion (NTE) analysis N2 - Zirconium vanadate (ZrV2O7) is a well-known negative thermal expansion (NTE) material which exhibits significant isotropic contraction over a broad temperature range (~150°C < T < 800°C). The linear thermal expansion coefficient of ZrV2O7 is −7.1×10-6 K-. Therefore, it can be used to create composites with controllable expansion coefficients and prevent destruction by thermal shock. Material characterization, leading to application, requires pure, homogenous samples of high crystallinity via a reliable synthesis route. While there is a selection of described syntheses in the literature, it still needs to be addressed which synthesis route leads to truly pure and homogenous samples. Here, we study the influence of the synthesis methods (solid-state, sol-gel, solvothermal) and their parameters on the sample's purity, crystallinity, and homogeneity. The reproducibility of results and data obtained with scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetric analysis (DSC/TGA) were analyzed extensively. The sol-gel method proves superior to the solid-state method and produces higher-quality samples over varying parameters. Sample purity also plays an important role in NTE micro and macro-scale characterizations that explain the impact of porosity versus structural changes. Moreover, we implement ab-initio-based vibrational computations with partially treated anharmonicity (quasi-harmonic approximation, temperature-dependent effective harmonic potentials) in combination with experimental methods to follow and rationalize the negative thermal expansion in this material, including the influence of the local structure disorder, microstructure, and defects. Khosrovani et al. and Korthuis et al., in a series of diffraction experiments, attributed the thermal contraction of ZrV2O7 to the transverse thermal motion of oxygen atoms in V-O-V linkages. In addition to previous explanations, we hypothesize that local disorder develops in ZrV2O7 crystals during heating. We are working on the experimental ZrV2O7 development and discuss difficulties one might face in the process as well as high-quality sample significance in further investigation. The obtained samples are currently used in the ongoing research of structure analysis and the negative thermal expansion mechanism. T2 - 16th International conference on materials chemistry (MC16) CY - Dublin, Ireland DA - 03.07.2023 KW - NTE KW - Sol-gel KW - Solid-state KW - Ab-initio KW - TDEP PY - 2023 AN - OPUS4-58134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander A1 - Hoffmann, V. A1 - Morcillo, Dalia A1 - Agudo Jácome, Leonardo A1 - Leonhardt, Robert A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique T1 - Investigation of degradation of the aluminum current collector in lithium-ion batteries by glow-discharge optical emission spectroscopy N2 - Lithium-ion batteries (LIBs) are one technology to overcome the challenges of climate and energy crisis. They are widely used in electric vehicles, consumer electronics, or as storage for renewable energy sources. However, despite innovations in batteries' components like cathode and anode materials, separators, and electrolytes, the aging mechanism related to metallic aluminum current collector degradation causes a significant drop in their performance and prevents the durable use of LIBs.[1] Glow-discharge optical emission spectroscopy (GD-OES) is a powerful method for depth-profiling of batteries' electrode materials. This work investigates aging-induced aluminum deposition on commercial lithium cobalt oxide (LCO) batteries' cathodes. The results illustrate the depth-resolved elemental distribution from the cathode surface to the current collector. An accumulation of aluminum is found on the cathode surface by GD-OES, consistent with results from energy-dispersive X-ray spectroscopy (EDX) combined with focused ion beam (FIB) cutting. In comparison to FIB-EDX, GD-OES allows a fast and manageable depth-profiling. Results from different positions on an aged cathode indicate an inhomogeneous aluminum film growth on the surface. The conclusions from these experiments can lead to a better understanding of the degradation of the aluminum current collector, thus leading to higher lifetimes of LIBs. T2 - European Winter Conference on Plasma Spectrochemistry (EWCPS 2023) CY - Ljubljana, Slovenia DA - 29.01.2023 KW - Lithium-ion batteries KW - Aging mechanisms KW - Depth-profiling PY - 2023 AN - OPUS4-56992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina A1 - Hesse, René A1 - Agudo Jácome, Leonardo A1 - Gonzalez-Martinez, I. T1 - Complex artificial features on a TEM transparent membrane N2 - The phenomenon of expelling nanomaterial from microparticles of different materials, such as Au, WO3 or B2O3 under the influence of a convergent electron beam (CB) of a transmission electron microscope (TEM) was reviewed by Ignacio Gonzalez-Martinez [1]. Converging the e-beam in a TEM means that a high amount of energy enters the microparticle at a very local place and interact with the matter. Obviously, during the convergent beam protocol, no imaging with the electron beam is possible, but at the end, nanoparticles with different appearances lie down next to the microparticle while its size is reduced. Hence, there is a blind spot in the observation, which we want to fill, as we want to help clarify the nature of the expelling phenomenon. One hypothesis that explains the phenomenon is the so-called damage (of the microparticle) induced by an electric field (DIEF). Within this theory, the material is ionized and expelled in form of ionic waves. Our aim is therefore to fabricate specimens with artificial microlandscapes, as schematically exemplified in figure 1a), using the focused ion beam (FIB) and micromanipulators, as experimental setups to follow the paths of the expelled material. As a first step towards the fabrication of such specimen, we make experimental feasibility studies for each fabrication method, FIB structuring with Ga+ ion beam and micromanipulated microparticle deposition. Bridges (gray regions in Fig. 1) are created by milling a commercially available electron transparent membrane (silicon oxide or carbon) of a Cu-TEM grid. Platinum or carbon walls (blue features in Fig. 1) are built to stand on those bridges. Microparticles (yellow sphere in Fig. 1) of gold or other material are deposited in the center of the bridges. Figure 2a) shows four square holes (black area) and between them the residual silicon oxide membrane bridges (dark grey). On top of the bridges, walls (light grey) are deposited. The width of the bridges is different, the walls overlap the holes as well as the distance between the walls is very small, so these and other parameters need to be optimized. Figure 2b) shows a square hole (black) with bridges (white) on the right side on top of a carbon membrane (grey). There are still some obstacles which needs to be eliminated. For instance, the deposition process of the walls is not reliable as visible at the wall on top where a hole arises instead of a wall. These studies are still in progress and the results are further discussed in terms of the applicability for the DIEF experiment in the TEM. T2 - 4th EuFN and FIT4NANO Joint Workshop / Meeting CY - Vienna, Austria DA - 27.09.2021 KW - Transmission electron microscope (TEM) KW - Sample preparation KW - Micromanipulation KW - Focussed ion beam growth KW - Nano-landscape PY - 2021 AN - OPUS4-58259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kang, M. A1 - Czasny, M. A1 - Kober, D. A1 - Reschetnikow, A. A1 - Stargardt, Patrick A1 - Mieller, Björn A1 - Gurlo, A. T1 - Influence of mica particle content in composites for high voltage applications produced by additive manufacturing and mold casting N2 - The insulation system of high voltage electrical devices like generators and electrical motors has to withstand thermal, electrical, ambient and mechanical influences (TEAM) during operation. Especially the dielectric properties have to satisfy the requirements also under elevated temperatures and extreme environments. To provide this high quality, the conventional fabrication process uses partly manually applied insulation tapes combined with a cost-intensive and under safety concerns at least problematic vacuum pressure impregnation step (VPI). In order to reduce process costs by increasing the degree of automation and avoiding the VPI process, additively manufactured (AM) insulations were studied. This study focuses on the fabrication of ceramic/polymer compounds via AM technique. The AM technology used a rotating screw extrusion print head with air pressure to supply the paste. Plate-like samples with dimensions of 55 mm x 55 mm x1mm thickness were produced. This work focuses on the homogeneously high viscous paste with 12.5 to 50 volume % ratio of filler particles. Three types of mica powders as ceramic filler materials with different particle sizes from micro to mm scale were evaluated. The controlled volume % ratio of particles affects the paste viscosity which enables stacking of paste layers with a viscosity close to clay pastes. The mixed pastes were cured by heating and UV light to increase mechanical properties. A TG/DTA was performed, and electrical properties were investigated. First experiments with respect to the dielectric properties such as volume resistance, permittivity and dielectric strength revealed promising results and the possibility to use AM techniques for the fabrication of high voltage insulations for electrical machines. T2 - MaterialsWeek 2021 CY - Online meeting DA - 07.09.2021 KW - HV-Insulation KW - Polymer-Ceramic-Composite KW - Additive manufacturing PY - 2021 AN - OPUS4-54368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina A1 - Gonzalez-Martinez, I. A1 - Agudo Jácome, Leonardo T1 - Damage induced by electric field of gold microparticles on silicon oxide substrate in the scanning electron microscope N2 - 1. Introduction A normally unwanted process that can arise when converging an electron beam onto, e.g. microparticles, has been called "damage induced by electric field" (DIEF) [1]. By DIEF, the convergent electron beam (CEB) imparts a high amount of energy to the microparticle locally and strongly interacts with its atoms. At a specific current density J, which can be controlled by the convergence angle α, the irradiated material begins to transform. The phenomenon of expelling nanomaterial from microparticles under the influence of a convergent electron beam (CB) in a transmission electron microscope (TEM) has been largely studied [2]. Several types of nanoparticles (NPs) have been observed for different metallic materials and metal oxides after specific CB protocols (P) in the TEM. Thus, DIEF can be used as a promising synthesis method controlled changes of micrometric material to create new nanometric material compositions and morphologies. While these reactions have been observed in situ at the high acceleration voltages associated with TEM, it remains unclear whether the SEM can also be used to fabricate NPs via DIEF. In contrast to TEM there is no possibility to statically convert the electron beam to a range of α to reach the needed J as in TEM. Instead, the scanning parameters and the magnification can be manipulated so as to find an integrated J. Considering that the scanning electron microscope (SEM) is easier to use, more accessible and cheaper than a TEM, here we explore the possibility to transfer the concepts of DIEF known to operate in the TEM for in situ NP generation SEM. 2. Objectives The main goal is to determine whether DIEF can be translated to the SEM perform to controlled in situ fabrication of nanoparticles from microparticles, using gold microparticles on amorphous SiO substrate as precursors. We determine what experimental parameters must be taken into account to create SEM-based CBPs for NP creation in the SEM with these materials. 3. Materials & methods Gold microparticles with diameter of around 1 to 3 µm were deposited on electron transparent amorphous SiO/SiO2 substrate. Using a convergent electron beam protocol (CBP) in a scanning electron microscope (SEM) at an acceleration voltage of 30 kV, the gold microparticles were irradiated until a production of NPs takes place as shown in figure 1. The beam current varied between 16 and 23 nA. 4. Results Depending on the CBP parameters, either only Au NPs or a mixture of Au and Si NPs are produced. The particle size ranges from a few nm up to 100 nm, and it depends on the distance of the NP to the initial position of the microparticle. Further beam parameters such as the dwell time, the effective irradiated volume and particle size determine whether NPs are produced or if the microparticles only are expelled from the substrate without reacting. 5. Conclusion The SEM can be used as an instrument for synthesizing nanomaterials via DIEF. Different CBP protocols can be applied for obtaining either gold nanoparticles or silicon + gold nanoparticles T2 - Microscopy Conference CY - Darmstadt, Germany DA - 26.02.2023 KW - Scanning electron microscopy (SEM) KW - Gold nanoparticles KW - Electron beam induced modification PY - 2023 AN - OPUS4-58261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Matthews, Lauren A1 - Sahre, Mario A1 - Hesse, R. A1 - Schusterbauer, Robert A1 - Grant, M. A1 - Agudo Jácome, Leonardo A1 - Albrecht, T. A1 - Hodoroaba, Vasile-Dan T1 - Approaches to Surface Analysis of Modified Quartz Nanopipettes N2 - Nanopipettes are a type of solid-state nanopore with needle-like geometry. Their applications range from imaging, sensing, diagnostics, and use as injectors. The response of nanopipette sensors is highly dependent on the size, geometry and chemical properties of the sensing region. As they are increasingly tuned and modified for specific analytes, a better understanding of the surface chemistry and morphology of the inner channel is necessary. With the aim of developing a comprehensive approach for characterisation of such nanopipettes, this research focuses on combining surface-sensitive analysis methods with advanced sample preparation techniques. Quartz substrates were modified by gas phase silanization, a well-utilised technique in the field to enhance performance of nanopipettes, and further functionalised with a metal bis thiolate complex, to aid in chemical analysis. The sample characterisation involved scanning electron microscopy (SEM), low-energy dispersive x-ray spectroscopy (EDX), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and Auger electron spectroscopy (AES). Using focused ion beam (FIB) milling under gentle conditions, the inner surface of quartz nanopipettes was exposed whilst preserving the integrity of the overall structure (see figure). Owing to the challenging analysis conditions, modification and analysis of flat quartz substrates has been performed in parallel for optimisation purposes. The results demonstrate the first steps towards full characterisation of nanopipettes at the nanoscale, notably with access to the inner channel. The methods used here can be applied to gain further understanding of the response of these sensors to complex analytes and allow for the study of different surface functionalisations at the all-important sensing region. T2 - European Conference on Applications of Surface and Interface Analysis (ECASIA 2024) CY - Gothenburg, Sweden DA - 09.06.2024 KW - Quartz nanopipettes KW - Nanopipette modification KW - Silanization KW - Surface analysis KW - Focussed ion beam PY - 2024 AN - OPUS4-60447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Battig, Alexander A1 - Abdou-Rahaman Fadul, Naïssa A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Schartel, Bernhard T1 - Multifunctional Graphene in Flame Retarded Polybutadiene/ Chloroprene/ Carbon Black Composites N2 - Multilayer graphene is investigated as a multifunctional nanofiller to polybutadiene/ chloroprene rubbers (BR/CR) that partially substitutes carbon black (CB) and aluminum trihydroxide (ATH). Loadings of only 3 parts per hundred rubber (phr) MLG replaced 15 phr of CB and/or 3 phr of ATH in BR/CR nanocomposites. Mechanical and fire behavior were investigated, and results point to improved rheological, curing and mechanical properties of MLG-containing rubber composites. T2 - 18th European Meeting on Fire Retardant Polymeric Materials, FRPM21 CY - Budapest, Hungary DA - 29.08.2021 KW - Graphene KW - Rubber KW - Fire Retardant KW - Nanofiller KW - Nanocomposite KW - ATH PY - 2021 AN - OPUS4-53202 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strommer, Bettina A1 - Böhning, Martin A1 - Schulze, Dietmar A1 - Schartel, Bernhard T1 - Natural Rubber Nanocomposites via Optimized Latex Premixing and Conventional Technical Processing N2 - Creation of highly functional materials and replacement of high amounts of conventional fillers are driving forces for the development of nanocomposites. Besides the type and properties of nanoparticles, their dispersing in the elastomeric matrix and the stability of this dispersion through all processing steps are the main factors for the resulting performance of the produced material. Therefore, a preparation chain via latex premixing to a highly filled masterbatch, followed by conventional technical processing is to be developed. Three types of carbon-based particles are characterized as such (SEM, Raman Spectroscopy, BET specific surface area) and in combination with natural rubber, as nanocomposites (TEM. Hardness, Abrasion resistance, Compression set, Cone calorimetry). All of the studied particles lead to an improvement in the investigated mechanical properties, the extent of reinforcement depends strongly on the specific surface of the particle interacting with the elastomeric matrix in combination with their shape. T2 - DKG Elastomer Symposium CY - Online meeting DA - 28.06.2021 KW - Processing KW - Elastomers KW - Nanocomposites KW - Graphene KW - Nanoparticles KW - Latex KW - Natural rubber PY - 2021 AN - OPUS4-53106 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schusterbauer, Robert A1 - Sahre, Mario A1 - Mrkwitschka, Paul A1 - John, Elisabeth A1 - Lange, Thorid A1 - Zurutuza, A. A1 - Jones, E. A1 - Donskyi, I. A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Correlative chemical imaging to reveal the nature of different commercial graphene materials N2 - Since the original report in 2004 by Novoselov and Geim, Graphene gained incredible attention due to its fascinating properties. In the past 20 years, the synthesis and functionalization of graphene has evolved significantly[3]. Different synthesis techniques were developed which led to other graphenerelated materials such as graphene oxide (GO) or elemental-doped graphene. Further chemical functionalization can enhance but also alter or reduce specific properties of the graphene. To reveal the nature of these materials a proper physico‑chemical characterization with different analytical techniques is crucial. Single-layer GO flakes kindly provided by Graphenea (Spain) were prepared for systematic image analysis. These flakes were disposed on an alignment-marked SiO2 substrate and correlatively imaged by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and Raman spectroscopy. The high lateral resolution and/ or extreme surface sensitivity of the mentioned techniques is necessary to explore monolayers. The ToF-SIMS images match well with the SEM and AFM images and provide information about the chemistry. With 2D Raman spectroscopy it is possible to differentiate between the number of stacked single-layer flakes. This is visualized in a 3D image (Figure b). Well-defined GO flakes could be used as a reference material for imaging of graphene-like structures but also of other types of 2D materials. In addition to these monolayer GO flakes, commercial graphene-containing inks (Haydale) with a more complex morphology were also correlatively imaged. ToF-SIMS and SEM images were merged to identify the origin of different chemical fragments. The findings correlate closely with the expectation that the specific functionalizations (with fluorine and nitrogen as marker elements) are present only on the graphene flakes as presumed from the SEM images. Energy-dispersive X-ray spectroscopy (EDX) supports these results, yet with a much lower sensitivity compared to ToF-SIMS. T2 - ECASIA 2024 CY - Gothenburg, Sweden DA - 09.06.2024 KW - Correlative imaging KW - ToF-SIMS KW - SEM KW - Graphene oxide flakes KW - Raman PY - 2024 AN - OPUS4-60680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schusterbauer, Robert A1 - Sahre, Mario A1 - Mrkwitschka, Paul A1 - John, Elisabeth A1 - Lange, Thorid A1 - Zurutuza, A. A1 - Jones, E. A1 - Donskyi, I. A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Correlative chemical imaging to reveal the nature of different commercial graphene materials N2 - Since the original report in 2004 by Novoselov and Geim, Graphene gained incredible attention due to its fascinating properties. In the past 20 years, the synthesis and functionalization of graphene has evolved significantly[3]. Different synthesis techniques were developed which led to other graphenerelated materials such as graphene oxide (GO) or elemental-doped graphene. Further chemical functionalization can enhance but also alter or reduce specific properties of the graphene. To reveal the nature of these materials a proper physico‑chemical characterization with different analytical techniques is crucial. Single-layer GO flakes kindly provided by Graphenea (Spain) were prepared for systematic image analysis. These flakes were disposed on an alignment-marked SiO2 substrate and correlatively imaged by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and Raman spectroscopy. The high lateral resolution and/ or extreme surface sensitivity of the mentioned techniques is necessary to explore monolayers. The ToF-SIMS images match well with the SEM and AFM images and provide information about the chemistry. With 2D Raman spectroscopy it is possible to differentiate between the number of stacked single-layer flakes. This is visualized in a 3D image (Figure b). Well-defined GO flakes could be used as a reference material for imaging of graphene-like structures but also of other types of 2D materials. In addition to these monolayer GO flakes, commercial graphene-containing inks (Haydale) with a more complex morphology were also correlatively imaged. ToF-SIMS and SEM images were merged to identify the origin of different chemical fragments. The findings correlate closely with the expectation that the specific functionalizations (with fluorine and nitrogen as marker elements) are present only on the graphene flakes as presumed from the SEM images. Energy-dispersive X-ray spectroscopy (EDX) supports these results, yet with a much lower sensitivity compared to ToF-SIMS. T2 - MaterialsWeek 2024 CY - Limassol, Cyprus DA - 17.06.2024 KW - Graphene oxide flakes KW - ToF-SIMS KW - SEM KW - Raman KW - Correlative imaging PY - 2024 AN - OPUS4-60681 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -