European Nanoanalysis Symposium (9th Dresden Nanoanalysis Symposium “on tour”)

Resume : I will show how an in-depth description of the basic principles of diffraction-unlimited fluorescence microscopy (nanoscopy) [1] has spawned a new powerful superresolution concept, namely MINFLUX nanoscopy [2-5]. MINFLUX utilizes a local excitation intensity minimum (of a doughnut or a standing wave) that is targeted like a probe in order to localize the fluorescent molecule to be registered. In combination with single-molecule switching, MINFLUX and its more recent ?cousin? MINSTED [6] have obtained the ultimate (super)resolution: the size of a molecule. Providing 1?3 nanometer resolution these novel microscopy concepts are being established for routine fluorescence imaging at the highest, molecular-size resolution levels. Relying on fewer detected photons than popular camera-based localization, MINFLUX and MINSTED nanoscopy are poised to open a new chapter in the imaging of protein complexes and distributions in fixed and living cells. [1] Hell, S.W. Nat. Methods 6, 24-32 (2009). [2] Balzarotti, F., Eilers, Y., Gwosch, K. C., Gynnå, A. H., Westphal, V., Stefani, F. D., Elf, J., Hell, S.W. Science 355, 606-612 (2017). [3] Eilers, Y., Ta, H., Gwosch, K. C., Balzarotti, F., Hell, S. W. PNAS 115, 6117-6122 (2018). [4] Gwosch, K. C., Pape, J. K., Balzarotti, F., Hoess, P., Ellenberg, J., Ries, J., Hell, S. W. Nat. Methods 17, 217-224 (2020) [5] Schmidt R., Weihs T., Wurm C., Janssen I., Rehman J., Sahl S.J., Hell S.W. Nat Commun 12:1478 (2021) [6] Weber, M., Leutenegger M., Stoldt S., Jakobs S., Mihaila T.S., Butkevitch A.N., Hell S.W., Nat. Photonics, https://doi.org/10.1038/s41566-021-00774-2 (2021).

Resume : Metal clusters supported on zeolites (metal@zeolite) are attractive due to their catalytic activity combined with zeolite shape selectivity [1]. Various synthetic strategies are used for rational preparation of metal@zeolite composites. The main goal of this study is to stabilize metal species and precisely control their size and distribution [2]. The understanding of the synthesis mechanisms and metal-zeolite interactions is still insufficient, thus the experimental and theoretical research of these materials is required [3]. Recently, we reported a series of metal@zeolite materials prepared using the 4-step ADOR (assembly-disassembly-organization-reassembly) strategy [4]. ADOR approach is based on topotactic transformation of UTL germanosilicate to layered precursor followed by organization of layers and reassembly of them generating a set of isoreticular zeolites (IPC family of materials). Utilization of this method allowed preparation of zeolites with various porosity with incorporated metal nanoparticles i.e. Pt@IPC-2 (OKO), Pt@IPC-4 (PCR) [4] and others. This set of materials consists of the same layers with different connectivity, which make them a suitable model to explore the dynamic structural evolution of metal clusters. Herein, we report the incorporation of rhodium species into ADOR zeolites. We investigated the dynamic structural change of Rh clusters and their thermal stability by performing in-situ heating of the material in scanning transmission electron microscope (STEM). Using a heating holder, we performed a step-wise temperature treatment (from the room temperature up to 700 oC) and analyzed changes in size of metal nanoparticles by STEM imaging. Moreover, properties of samples were investigated by PXRD, sorption of Ar, SEM, and EDS. Catalytic performance of prepared materials was tested in hydrogenation of nitriles. Chemical properties and architecture of the of zeolite support play a significant role in the formation and stability of Rh nanoparticles. References 1. Liu, L. C., Corma, A., Nature Reviews Materials (2020) 1-20 2. Wang, H., Wang, L., Xiao, F. S., ACS Central Science 6 (2020) 1685-1697. 3. Liu, L. C., Zakharov, D. N., Arenal, R., Concepcion, P., Stach, E. A., Corma, A., Nature communications 9 (2018) 574. 4. Zhang, Y. Y., Kubu, M., Mazur, M., Cejka, J., Microporous and Mesoporous Materials 279 (2019) 364-370.

Resume : Correlating HR-TEM and XPS to elucidate the core-shell structure of ultrabright CdSE/CdS semiconductor quantum dots Jörg Radnik(1), Florian Weigert (2), Ines Häusler (3), Daniel Geißler (2), and Ute Resch-Genger(2) 1 Federal Institute for Material Research and Testing (BAM), Division 6.1 Surface Analysis and Interfacial Chemistry, Unter den Eichen 44-46, 12203 Berlin Germany; 2 Federal Institute for Material Research and Testing (BAM), Division 1.2 Biophotonics, Richard-Willstätter-Str. 11, 12489 Berlin Germany 3 Technische Universität Berlin, Institut für Optik und Atomare Physik, Straße des 17. Juni 135, 10623 Berlin, Germany Controlling the thickness and tightness of surface passivation shells is crucial for many applications of core-shell nanoparticles (NP). Usually, to determine shell thickness, core and core/shell particle are measured individually requiring the availability of both nanoobjects. This is often not fulfilled for functional nanomaterials such as many photoluminescent semiconductor quantum dots (QD) used for bioimaging, solid state lighting, and display technologies as the core does not show the application-relevant functionality like a high photoluminescence (PL) quantum yield. This calls for a whole nanoobject approach. Moreover, the thickness of the organic coating remains often unclear. By combining high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS), a novel whole nanoobject approach is developed representatively for an ultrabright oleic acid-stabilized, thick shell CdSe/CdS QD with a PL quantum yield close to unity. The size of this spectroscopically assessed QD, is in the range of the information depth of usual laboratory XPS. Information on particle size and monodispersity were validated with dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) and compared to data derived from optical measurements. The results of the different methods match very well within the different measurement uncertainties. Additionally, results obtained with energy-resolved XPS using excitation energies between 200 eV and 800 eV are discussed with respect to a potential core/shell intermixing. Moreover, the future application potential of this approach correlating different sizing and structural methods is discussed considering the method-inherent uncertainties and other core/multi-shell nanostructures. The authors gratefully acknowledge financial support from the German Research Foundation (DFG grant RE1203/12-3) and from the European Metrology Programme for Innovation and Research (EMPIR) as part of the project 14IND12 INNANOPART.

Resume : To enable the development of technology fields, such as artificial intelligence and big data, integrated circuits, also called microchips, have to meet new performance requirements. This can be achieved by scaling down the transistor size and increasing the density of the device. This area scaling in the front-end of line (FEoL) is connected with an even accelerated size reduction in the back-end of line (BEOL), the so called interconnects, and leads to smaller metal pitches and reduced cross-sectional areas of the wires. But this size reduction to the smaller nanometer range is connected with many material challenges, due to an increasing resistance-capacitance (RC) delay. In order to reduce the resistance of the interconnects, novel diffusion barriers with a lower resistivity are integrated and the thickness of them is reduced to a minimum. Additionally the standard interconnect material copper is replaced by other metals, such as ruthenium or cobalt. Although those metals have a higher bulk resistivity than copper, due to their shorter electron mean free path, a resistance reduction can be achieved in small features with critical dimensions below 15 nm [1]. To maintain the functionality and reliability of the device it is therefore necessary to understand the diffusion mechanism at the interfaces of the new integrated materials. In our work we used X-ray photoelectron spectroscopy depth profiling (XPS-DP) to describe the diffusion of interconnect metals into novel barrier materials, consisting of different metal alloys. Diffusion was induced by annealing of the material stacks at different temperatures in a rapid thermal annealing system. Following we applied the Mixing-Roughness-Information Depth (MRI) model, which was developed by Hofmann et al. [2], to estimate the diffusion coefficients from the XPS depth profiles. The MRI model describes the depth resolution function (DRF) of the sputter profiles and hence can account for the sputter-induced broadening of the depth profile. The model is based on three physical well defined parameters, atomic mixing (w), information depth (?) and roughness (?), that are described by 3 different functions. The convolution of those functions will give the DRF. Following the roughness parameter (?) can be used to quantify the diffusion as it is directly correlated to the diffusion by the relation: ?2= 2Dt [2]. Hence by applying the model to the XPS depth profiles of the as-deposited thin film stacks as well as to the annealed stacks, diffusion coefficients can be estimated and the diffusion behavior at the interface of those novel materials can be directly compared. Additionally to the just described simple MRI model, an extended version was used to account for preferential sputtering in some of the thin films stacks. Here the concentration depth profile will be corrected by the different sputter rates of the materials by applying a differential equation that describes the surface concentration in the mixing zones [3]. In summary we show that this analysis method is suitable to quantify the diffusion in different thin film stacks and that it can be used to describe the diffusion mechanisms in interconnects in more detail. [1] M. Naik, ?Interconnect Trend for Single Digit Nodes?, IEDM 2018 [2] S. Hofmann, Auger- and X-Ray Photoelectron Spectroscopy in Materials Science, Springer, 2013, p. 349-350 [3] S. Hofmann et al., 2019, Preferential sputtering effects in depth profiling of multilayers with SIMS, XPS and AES, Applied Surface Science 483, p. 140?155.

Resume : Scanning electron microscopy (SEM) has been proven a very useful tool for the characterization of material surfaces and composition. In the last decades, image analysis techniques have been utilized to make SEM-based characterization more quantitative, automate, and accurate. A very common application of these techniques has been the segmentation of back-scattered SEM images (BCS) of complex materials that consist of areas with different chemical composition. However, segmentation results are greatly affected by image acquisition and processing settings undermining their reliability. In this work, we investigate these effects and focus on the optimization of image acquisition parameters to maximize the accuracy of the segmentation process. In particular, we propose a new methodology to quantify the ability of a grayscale image to be segmented successfully. The method combines the intensity information arising from regions related to different mean atomic number with their corresponding spatial distribution. The impact of this index in image metrology is not limited only to the optimization of the image acquisition process but could be a guideline for a more robust BCS SEM analysis. In order to validate the proposed method, we utilize synthetic BCS images of multiphase materials generated using a novel non-iterative method, where acquisition parameters can be controlled.

Resume : Erbium doped silicon oxide thin films have emerged as promising materials for optical device. However, the photonic properties in such system are strongly dependent on the nanostructure such as the spatial distribution of Er atoms, silicon nanoclusters formation or silicate phase formation [1-2]. These issues have remained difficult to observe in practice by conventional techniques. Atom probe tomography (APT) has emerged as a unique technique that is able to provide information about the chemical composition of elements together with a 3D map indicating the position of each atom from a specimen thus allowing a complete picture of nanostructural evolution [3-4]. The objective of this work is to correlate the evolution of the nanostructure of high Er doping of silica matrix at atomic scale studied by APT and TEM as function of Er content and for different annealing processes. Optical properties have been measured by cathodo- and photo-luminescence and correlated to structural and chemical results. We observe that in APT studies, we can locate Er atoms and determine matrix phases chemistry allowing to follow the phase decomposition and the dopant location. TEM experiments revealed in both case a segregation of two phases interconnected attributed with the help of APT to Er-rich and Si-rich phases. The type of annealing allows to have different Er distribution and nanostructuration which are directly linked with the optical properties [5]. [1] A. Kenyon et al. Semiconductor Science and Technology, 20 (2005) 65 [2] G. Beainy et al. Journal of Alloys and Compounds 755 (2018) 55 [3] W. Lefebvre et al. Atom probe tomography: put theory into practice (2016) [4] D. Blavette et al. Rev. Sci. Instr., 64 (1993) 2911 [5] R. Lo Savio et al. Appl. Phys. Let., 93 (2008) 021919

Resume : Scanning electron microscopy (SEM) and atomic force microscopy (AFM) are two of the most used, complementary techniques for surface analysis at the nanoscale. Integrating a compact AFM into SEM brings new possibilities for true correlative microscopy and advanced multi-modal sample characterization that would be often unfeasible using each imaging modality separately. Thus, this approach is beneficial in various fields, such as Material science, Nanotechnology, Semiconductors, or Life science. Correlative Probe and Electron Microscopy (CPEM) represents a hardware correlative technology, enabling simultaneous acquisition of SEM and AFM data, and seamless correlation into one 3D image. The strength lies in a combination of AFM modes (3D topography, electrical, mechanical, and magnetic measurements) and SEM capabilities (fast imaging with wide resolution range, chemical analysis, surface modification). CPEM technique can be applied using LiteScope 2.0, produced by NenoVision, ensuring the data are collected in the same coordinate system and with identical pixel size, resulting in 3D complex multi-channel sample characterization. Above mentioned advantages can be demonstrated on correlative in-situ analysis of LiNiO2 cathode material used in rechargeable batteries. Since the powdered cathode material is prone to rapid oxidation upon air exposure, it would represent a complicated sample for standard AFM and SEM systems and needs to be analyzed by the AFM-in-SEM approach. The SEM combined with EDX technique provided fast navigation of the AFM probe on the sample, information of elemental composition, and material contrast. The AFM LiteScope was used to measure the sample topography and conductive mapping to characterize the changes in the cathode after charge/discharge cycling. Lastly, the correlated CPEM image combines AFM topography with SEM material contrast and provides straightforward data interpretation. As we can see, the AFM-in-SEM strategy benefits from the complementarity of both techniques alongside significant savings both in time and resources. Furthermore, in-situ analysis and CPEM technology open doors to new possibilities for advanced data correlation and measurements in many areas of both research and industry.

Resume : Ti-stabilized 15%Cr-15%Ni stainless steels such as the AIM1 steel developed by CEA in France are currently the reference material for fuel-pin cladding of GEN-IV sodium-cooled fast nuclear reactors. The main issue regarding these steels is to control their evolution during irradiation in terms of swelling and more generally the distribution of chemical species. The microstructural and chemical properties at high dose (>100 dpa) that lead to swelling, are strongly dependent on the irradiation temperature, the initial microstructure and the first microstructural evolutions occurring under irradiation, which have been studied in the present work. Neutron irradiation can be usefully modelled by ion irradiation, which is more practical and enables analytical study of the irradiation parameters. This work presents a multi-scale microstructure analysis of the effect of ion irradiation on the AIM1 material with two initial microstructures having different densities of crystalline defects: solution annealed (low defect density) and 20% cold-worked (high density of dislocations and mechanical twins). Ni2+ ion irradiations were carried out on these samples at 450°C and 550°C with two fluences to obtain a progressive dose ranging from 3 dpa to 10 dpa. SEM-EBSD and optical microscopy analyses were performed on non-irradiated samples to characterize the microstructure at grain scale. In addition, TEM and APT studies were initiated in a complementary way to acquire information at nano and atomic scale and complete micro-scale characterization. Optical microscopy characterization illustrates the complexity of non-irradiated microstructure with large bands of precipitates like (Ti, Mo)(C, N). SEM-EBSD analyses provide information on the density of dislocations, thermal and mechanical twins. TEM and APT analyses were carried out to characterize non-irradiated and irradiated microstructures for comparison at a local scale. Ni and Si local enrichments are observed after only 3 dpa. This segregation is nanoscaled, homogeneously dispersed throughout the microstructure of the cold-worked state and linked to the initial dislocation network highlighted in TEM. The lack of this initial network favors segregation of beneficial elements to swelling resistance if they remain in solution. After 10 dpa a strong density of MC precipitates was highlighted. This microstructural multi-scale study before and after low dose irradiation provides essential information to understand the microstructure influence and its evolution leading to the nucleation of precipitates, Frank loops and consequently control the swelling resistance.

Resume : It sounds like being a simple analytical task, it is definitely not. The way toward accurate measurement of the size distribution of nanoparticles (NPs) with complex shape, having a broad size polydispersity, with inhomogeneous chemistry, and with a high degree of agglomeration/aggregation is very challenging for all available analytical methods. Particularly for the NPs with complex shape, the access to the smallest dimension (as e.g. required for regulatory purposes) can be enabled only by using imaging techniques with spatial resolution at the nanoscale. Moreover, the full 3D-chacterisation of the NP shape can be provided either by advanced characterization techniques like 3D-TEM tomography or by correlative analysis, i. e. synergetic/complementary measurement of the same field-of-view of the sample with different probes. Examples of the latter type of analysis are: i) electron microscopy for the lateral dimensions and AFM for the height of the NPs, ii) SEM with STEM-in-SEM (also called T-SEM), iii) Electron Microscopy with TKD (Transmission Kikuchi Diffraction) for determination of the geometrical orientation of crystalline NPs, iv) Raman and SEM for e.g. thickness of graphen flakes, or v) Electron Microscopy for descriptive NP shape and SAXS for the NP concentration, the latter as a NP property able to be measured with higher and higher accuracy. For all these types of measurement, reference NPs are necessary for the validation of the measured size. Particularly non-spherical reference NPs are still missing. Examples of such new reference NPs as characterized by the correlative analyses enumerated above will be presented in detail in the contribution. Acknowledgement: This project 17NRM04 nPSize has received funding from the EMPIR programme co-financed by the Participating States and from the European Union?s Horizon 2020 research and innovation programme.

Resume : The aim of the study was to use correlative microscopy and spectroscopy methods to investigate precipitates in Inconel 625 additively manufactured by laser powder bed fusion (L-PBF). The microstructure of additively manufactured alloys consists of paths resulting from the bonding of powder particles by the laser beam, in which the rapidly solidified melt pools are distinguished. Inside them, a fine grain with a very fine cellular-dendritic structure is present. Thus, characterization of the microstructure of L-PBF Inconel 625 requires research on a different scale and in various aspects. Multi-scale characterization of the precipitates was performed using complementary SEM, TEM, HRTEM, and STEM electron microscopy imaging techniques combined with electron diffraction and spatially resolved EDS microanalysis. Structural and chemical analysis allowed to identify the existing phases and determine the partitioning of the constituent elements between the matrix and precipitates. The results of TEM, STEM and EDS mapping revealed that microsegregation of Nb and Mo to the cell boundaries promotes the precipitation of NbC carbides and Laves phase particles rich in Ni, Cr, Mo, Nb and Si. Furthermore, the correlation of the STEM-HAADF images with EDS microanalysis and selected area electron diffraction with beam precession (PED) and allowed the identification of Al2O3 oxide nanoparticles. To examine the evolution of precipitates at high temperature, specimens of the Inconel 625 L-PBF were subjected to annealing at a temperature range of 600-800 °C and the duration varied from 5 to 500 hours. Combination of several electron microscopy techniques enabled to determine that after annealing at 600 °C from 5 to 500 hours and at 700 °C for 5 h, fine disc-shaped nanoparticles of the Nb-rich metastable gamma'' phase were present. Prolongation of the annealing duration and increase of temperature to 800 °C resulted in the transformation of the gamma'' phase to thermodynamically more stable delta phase, precipitation of the Cr-rich M23C6 carbides and subsequently the growth of the precipitates. Between them, the Laves phase particles were characterized by the high density of planar defects. According to the use of correlative microscopy and spectroscopy methods, the precipitates in the L-PBF Inconel 625 subjected to high-temperature annealing were characterized at microscale and nanoscale.

Resume : Inorganic lanthanide-doped upconversion nanoparticles (UCNP) present an emerging class of near-infrared (NIR)-excitable luminescent reporters for the life and material sciences with applications in bioimaging, fluorescence assays, optical sensing, and optical thermometry as well as phosphors for photovoltaic and security applications.1 The use of UCNP in bioimaging and cellular studies requires biocompatible particles. One possible cause of UCNP toxicity is the release of potentially harmful fluoride fluoride and lanthanide ions as revealed by dilution studies in aqueous environments, particularly under high dilution conditions.2-5 To address this issue, suitable surface coatings preventing such effects in combination with fast screening methods suited for online in situ analysis are desired. Here we present a systematic study of differently sized ?-NaYF4:Yb,Er nanocrystals stabilized with different surface coatings and different hydrophilic ligands varying in binding strength to the surface atoms in various aqueous environments at different temperatures. Particle disintegration was confirmed by transmission electron microscopy studies of the differently aged UCNPs and changes in surface composition were determined by energy-dispersive X-ray spectroscopy (EDXS). The concentration of the fluoride ions released upon particle dissolution was quantified electrochemically with a fluoride ion-sensitive electrode and monitored fluorometrically, thereby exploiting the sensitivity of the upconversion luminescence to changes in size and surface chemistry. The excellent correlation between the changes in luminescence lifetime and fluoride concentration highlights the potential of using luminescence lifetime measurements for UCNP stability screening and thereby indirect monitoring of the release of potentially hazardous fluoride ions during uptake and dissolution in biological systems. Additionally, the developed in situ optical method can be used to distinguish the dissolution dynamics of differently sized and differently coated UCNPs. Based upon our results, we could derive optimum screening parameters for UCNP stability studies and determine conditions and coating procedures enhancing UCNP stability. 1. Guo, H.; Sun; S., Nanoscale, 2012, 4, 6692-6706. 2. Lisjak, D.; Plohl, O.; Ponikvar-Svet, M.; Majaron, B., Rsc Advances 2015, 5 (35), 27393-27397. 3. Lisjak, D.; Plohl, O.; Vidmar, J.; Majaron, B.; Ponikvar-Svet, M., Langmuir 2016, 32 (32), 8222-8229. 4. Plohl, O.; Kraft, M.; Kova?, J.; Belec, B.; Ponikvar-Svet, M.; Würth, C.; Lisjak, D.; Resch-Genger, U., Langmuir 2017, 33 (2), 553-560. 5. Lahtinen, S.; Lyytikäinen, A.; Päkkilä, H.; Hömppi, E.; Perälä, N.; Lastusaari, M.; Soukka, T., J. Phys. Chem. C 2017, 121 (1), 656-665.

Resume : Innovative products and new technologies require the design and synthesis of materials with a preassigned set of tailored properties. The design of advanced engineered materials needs accurate information about the 3D morphology, and its changes, both during materials synthesis and product manufacturing as well as during the operation of the product. More and more, advanced engineered materials are hierarchically structured, i.e., the description of the material needs multi-scale modeling and characterization (from the atomic scale to macro scale). Because of the high ratio of sample thickness to spatial resolution (about 103), X-ray computed tomography (XCT) is a unique non-destructive technique for the multi-scale imaging of the 3D morphology and of kinetic processes during materials synthesis and materials aging. The high accuracy of 3D data from nano-XCT with sub-100nm resolution can be ensured by applying machine learning algorithms for the correction of imaging artifacts to compensate for experimental inaccuracies such as misalignment and motions of samples and tool components [1]. The signal-to-noise ratio (SNR) of X-ray microscopy images (2D projections) is often low using absorption contrast and "standard protocols", particularly in the case of materials composed of low-Z elements and of material components with nearly the same atomic number Z. Therefore, SNR has to be optimized to enable acceptable image acquisition times for nano-XCT. Two options for SNR improvement are to increase either the number of collected projections or the exposure time. So far, the result and the efficiency of the chosen option can be assessed only after the image acquisition for all projections has been completed. An increase in the number of attempts is time-consuming and can lead to sample degradation, particularly for biological objects and organic materials. We present a monitored reconstruction approach [2], in which the acquiring of projections is interspersed with image reconstruction. The monitored reconstruction model allows examining the tomographic reconstruction process as an anytime algorithm and finding the optimal stopping point, corresponding to the required number of X-ray projections for the currently imaged object. This approach reduces the average image acquisition time. Due to stopping at different times for different objects, the proposed approach allows achieving a higher mean reconstruction quality for a given mean number of X-ray projections. A poor SNR in the measured projections unexceptionally complicates the automatic analysis of reconstructed images. For illustrative purposes, we analyze the problem of automatic binarization for 3D tomographic data of a porous structure [3] (one of the representatives of functional materials) by the unbalanced Otsu method. We outline the theoretical framework for the problem, propose a physically based criterion for optimal filtering, and provide its experimental evaluation. According to the introduced rule, a representative volume of the analyzed image is selected. To minimize the time required to calculate the optimal parameters, their calculation is carried out on the representative volume. This work was partially financially supported by RFBR 8-29-26020, 20-07-00933. 1. E. Topal et.al. DOI: 10.1038/s41598-020-64733-7 2. K. Bulatov et.al. DOI: 10.1109/ACCESS.2020.3002019 3. M. Chukalina et.al. DOI: 10.18287/2412-6179-CO-781

Resume : Mechanical failures in microelectronic devices, such as delamination and cracking, play a key role for reliability concerns in modern Back-End-of-Line (BEoL) structures. Many ways have been presented in literature on how to evaluate interfacial toughness parameters in BEoL stacks. Most standardized are methods based on double cantilever beam- and four-point bending. Beside the macroscopic methods there also are micromechanical testing procedures that allow to characterize the structures of integrated circuits in a more localized manner. Examples for micromechanical methods are the cross-sectional nanoindentation, FIB-prepared cantilever experiments or stressed overlayer buckling experiments. In this study a novel micromechanical testing approach is presented, that enables the investigation of Cu test structures in different loading modes. The geometry of the Cu test structures resembles interconnect structures of BEoL stacks. For this approach, a FIB-prepared customized diamond indenter tip is utilized to laterally load Cu-test structures and provoke a delamination during testing. After testing the delaminated area can be investigated by SEM pictures and FIB cross sections to determine the delaminated interface. Goal of this study is to depict the stress distribution in the test structures and to evaluate interfacial toughness parameters that can be used as input for FEM simulations.

Resume : Nanoindentation enables testing mechanical properties on a very small length scale. Consequently it is usually combined with a high resolution imaging system, to correlate mechanical properties to the structure of the object. These imaging techniques are mostly based on optical microscopy, scanning probe techniques or scanning electron microscopy. They only provide a detailed image of the sample surface, while a high voltage SEM beam can penetrate the surface by 1-3 µm. Here we present the advantages of the modular approach of the sm@rt 500 nanoindenter. The conventional large-range nanoindentation head can be combined with a high frequency ultrasound transducer. This transducer enables us to create a 3D map of the sample prior to the mechanical testing. This offers new possibilities for material testing: Since the elastic field of deformation is long ranging -even with sharp tips-, quantitative testing requires homogeneous samples. With the analysis of elastic ultrasonic waves, sample heterogeneities can be detected, avoided or addressed.

Resume : The scientific and technological interest in graphene has been growing more and more in the late years due to its outstanding properties and diverse promising applications. However, graphene implementation into the industrial market is still limited and many challenges are yet to be addressed before this material can become suitable for the large-scale production. One of the most crucial challenge to overcome is to develop reliable and reproducible ways to characterize the material properties which can heavily affect the product performance. In our study the chemical composition of nine different samples of industrial graphene, graphene oxide and functionalized graphene were investigated. The samples were analysed both in form of powder and pellets. A comparative characterisation of the chemical composition was performed through X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive X-ray Spectroscopy (EDX). XPS depth resolution is in the order of 10 nm, while for EDX the analysis was performed at two different energy levels, i.e. 5 keV and 15 keV, and thus varying the analysis depth from 200 nm to 2000 nm. The XPS measurement area is 300x700 µm² while the EDX measurement was performed by analysing a grid of 25 locations (5x5) of 150 x 150 ?m2 area, covering the whole pellet surface of 5 mm diameter and then calculating the mean of the elemental concentration. The results of the elemental concentration values from XPS and EDX analyses show a good agreement for all the elements presents in the samples, despite the different spatial resolutions of the two techniques. Therefore, the samples appear homogeneous both in the lateral and vertical directions. The results relative to powder and pellets samples do not differ in a significant way except for a slight increase in the carbon content regarding the pellet samples, probably due to a minor contamination effect introduced through pressing. Nevertheless, pellets samples appear to be quite representative for the material while being much more convenient in terms of handling and safety compared to nano-powders and providing a regular flat surface for EDX analysis. Finally, this approach correlating XPS and EDS represents a simple, fast and reliable way for characterizing the chemical composition and the homogeneity of industrial graphene. This study is part of the project ?Standardisation of structural and chemical properties of graphene? (ISO-G-SCoPe) which has received funding from the EMPIR programme co-financed by the Participating States and from the European Union?s Horizon 2020 research and innovation programme under Grant agreement No. 19NRM04.

Resume : Scanning electron microscopy (SEM) is considered to be a versatile and powerful technique for the examination of a wide range of materials. While secondary electron emission is the main signal used for the production of (SEM) images, back-scattered electron (BSC) images providing information of the mean atomic number (Z) are invaluable in the study of multiphase materials. In this work, the contrast and brightness of BSC images, acquired by a thermionic gun microscope, are thoroughly investigated. In particular, they are studied as a function of relevant image acquisition experimental parameters for the case of model specimens resembling very low Z-difference multiphase materials. Moreover, the mean value and the variance of the pixel intensity of images are related to the contrast and brightness microscope adjustments as well as the specimens being measured. Finally, the application of a Gaussian mixture model for the deconvolution of the overall intensity distribution to its components and subsequent comparison to the corresponding experimental constituents is utilized to show that there is a range of experimental conditions optimizing the acquired Z-contrast BSC images.

Resume : Selective hydrogenation catalysts play a key role in many industrial processes, but they are primarily based on supported noble metals, such as Pt and Pd, which are usually dispersed in nanoparticles. However, the production and recovery of these noble metal nanoparticles is a very energy-consuming and expensive procedure. Accordingly, replacing these metals by other inexpensive, transition metals such as Fe and Cu without sacrificing the activity and selectivity of these catalysts, will necessarily reduce their production costs. Moreover, choosing Zeolites as a support gives the advantage of shape selectivity to the desired product. In this study, we develop an alternative method for preparing hydrogenation catalysts composed of metallic nanoparticles encapsulated into zeolite frameworks through reductive demetallation of Fe-zeolites or Cu/Fe-zeolites with MFI topology. Particularly, the process of reductive demetallation is described using temperature-programmed reduction (TPR) and Mössbauer Spectroscopy data. The reductive demetallation of Fe-MFI, that is its Fe extraction from zeolite framework and formation of Fe0 nanoparticles starts at the temperatures above 800? and finishes at 1035? when sintering occurs strongly. In contrast, introduction of second metal leads to decrease in reduction temperature, as process of CuFe@MFI formation finishes at 800?. Both Fe@MFI and CuFe@MFI show activity in p-nitrotoluene hydrogenation to p-toluidine. Conversion of the substrate grows with increase in Copper and Fe loading. Thus, this synthesis method of encapsulation of Fe-Cu nanoparticles into the zeolite framework through reductive demetallation of Fe-zeolite can be used to prepare hydrogenation catalysts

Resume : In the last years, the increasing popularity of chaos theory in the analysis of various signals is seen. This is true also for tribological testing, where the nonlinear properties of the tribosystems are examined. For example, recently chaos theory was proposed as a tool for determining the machinability of steels, as well as predicting the reliability of bearing materials. In this work, a new approach to the analysis of tribological phenomena with the use of their nonlinear characteristics is proposed. The signals of coefficient of friction will be analyzed using recurrence quantification analysis (RQA) and principal component analysis (PCA). The synergy of the observed phenomena will be discussed along with the microscopic images which present the surface state of the samples. Moreover, preliminary results on the applicability of composite multiscale entropy (CMSE) in the analysis of microscopic images acquired for friction tracks of coated metals will be presented. According to the findings, the proposed novel approach to analyzing tribological signals offers a valuable insight into the friction and wear phenomena of coated metals. With the use of both microscopic observations of the wear tracks, as well as tools for the determination of nonlinear characteristics of the tribopair, new information which is not available with the use of conventional analysis methods can be obtained. The successful application of RQA, PCA, and CMSE in tribotesting will be presented for data, which was acquired during the actual wear tests, as well as the analyses of coated alloys. The presented methods can be used also in the analysis of other signals, in particular microstructures. Acknowledgements: The work was supported by the National Science Centre (Poland) within the PRELUDIUM 13 grant proposal, project no. UMO-2017/25/N/ST8/02270.

Resume : Intermetallic compounds based on aluminum reveal many perspective functional properties including catalytic activity in reactions relevant for industry. Among them, the Al-Fe phases are a frequently discussed topic, due to the composition containing cheap, easily available and environmentally friendly elements. Previous research most often used single crystal growth methods to prepare these compounds. To ensure the industrial application of these materials, an easy and effective way of manufacturing is required. Therefore, the melt spinning method, that enables obtaining materials with a narrow range of phase composition and ensures favorable properties to catalyst preparation has been proposed. The research focused on manufacturing the Al-Fe melt-spun alloys and structural examination of the obtained ribbons. The compositions of produced materials refer to selected intermetallic phases revealing unique structure that ensures catalytic activity. The initial alloys composed of Al76.5Fe23.5 and Al71.5Fe28.5 (in at.%) were induction melted and then remelted and cast onto the rotating copper wheel in the melt spinning process. The obtained materials were in the form of brittle flakes 50-70 µm thick. To ensure structural homogeneity, part of the ribbons were annealed in temperatures chosen basing on the Al-Fe phase diagram. The phase composition of obtained ribbons was investigated by the x-ray and electron diffraction methods. The microstructure was examined using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The Al76.5Fe23.5 alloy in the melt-spun state contained a monoclinic Al13Fe4 phase and Al solid solution located on the grain boundaries of the primary phase. After heat treatment at 500 °C for 72 h, the Al solid solution dissolved, and a single-phase Al13Fe4 structure was obtained. The ribbon cross-section revealed a microstructure containing columnar dendrites. The Al71.5Fe28.5 alloy in the initial and heat-treated state revealed a single-phase composition. The TEM and XRD studies confirmed the presence of the orthorhombic Al5Fe2 phase in both examined stages. In addition, the SEM studies showed high homogeneity of the material microstructure. The catalytic properties of examined materials were tested for pulverized ribbons in the reaction of partial hydrogenation of phenylacetylene. All examined materials revealed catalytic activity. The highest selectivity to styrene of 70%, was obtained for Al13Fe4 in the initial state, while the other materials showed selectivity in the range of 60%. The goal of preparing single-phase intermetallics exhibiting catalytic activity was achieved. The continuation of this research will be focused on the improvement of catalytic properties by the enlargement of specific surface area in the dealloying process. Acknowledgments: This work was financially supported by the National Science Centre (NCN) Poland within the project No. 2017/25/B/ST8/02804

Resume : The (Cr3C2-25(Ni20Cr))-(Ni-graphite) deposits are excellent candidates for a wide range of applications in machine parts both in the automotive and aerospace industries. The composite coatings containing the solid lubricant protect coated substrates and ensure the performance of the lubrication. These coatings were cold sprayed on the Al 7075 alloy and austenitic steel substrates using high-pressure cold spray system Impact Innovations 5/8 with robot Fanuc M-20iA and positioner ZAP ROBOTYKA. A D8 Discover diffractometer was used to study the phase composition and residual stresses of the sprayed deposits. The microstructure was characterised based on observations carried out using the scanning electron microscope FEI E-SEM XL 30. To investigate the coating microstructure in micro/nanoscale areas FEI TECNAI G2 transmission electron microscope was used. The thin foils for transmission electron microscopy studies were cut with a FIB technique using an FEI QUANTA 3D Dual Beam. A CSM Instruments low-load Vickers tester was used to determine the coating hardness in the cross-section. The adhesion test was carried out by Positest AT-A device. The abrasive wear tests were carried out using an ITEE T-07 tester and loose abrasive Al2O3 particles. The tribological tests were carried out on the ball-on-disk tribometer T-21 under different loads and temperatures. The mechanical, tribological and adhesion properties of (Cr3C2-25(Ni20Cr))-(Ni-graphite) coatings sprayed on the two different substrates were investigated and correlated with their microstructure. Observations of the microstructure revealed a homogeneous distribution of Cr3C2 and Ni-graphite phases in the coatings regardless of the substrate used. Severe plastic deformation of powder particles, adiabatic shear instability and mechanical interlocking ensured the strong adhesion of the coatings. The mechanical and tribological properties of the (Cr3C2-25(Ni20Cr))-(Ni-graphite) deposits differed depending on the coated substrate. Acknowledgements This work is financially supported by the National Science Centre, Poland (Project No 2017/25/B/ST8/02228).

Resume : The 0.78%C-1.67%Si, 2.45%Mn, 1.35%Cr, 0.21%Mo, 1.30%Al, bal. Fe (all in wt. %) steel after hot-rolling and austenitization at 950°C for 30 min was isothermally heat treated at three different temperatures: 180°C, 200°C and 220°C for 0,5h ? 24h to produce a nano-structured bainite. Depending on heat treatment conditions of steels, it is possible to obtain various morphology of bainite. In the range of 0.5h - 4h for all three studied temperatures the average hardness and austenite concentration were 635 HV and 1.6%, respectively. The samples microstructure showed mixture of bainitic ferrite surrounded by thin films of austenite. In the range time of 4 - 24h, significant changes in phase composition was observed. At 220°C hardness decreases to 502 HV due to increases of the austenite concentration up to 13,0% and coarsening of bainitic laths. With the increasing time of soaking the carbon content in austenite gradually exceeded the overall amount, while with the increase of temperature the carbon content in austenite increased in the first range of treatment with a simultaneous decrease of ferrite content in the whole range of isothermal heat treatment.