EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The search for more effective as well as novel functional materials, such as heterogeneous catalysts, would benefit when we could bridge the molecular world with the macroscopic world, which involves materials performance.

Such detailed information can be obtained if we would have access to a very powerful camera probing the dynamics of a functional material when it is at work. By shooting...

Interfaces govern the behaviour of all electronic devices. Herbert Kroemer coined the famous phrase “the interface is the device” in his 2000 Nobel Prize lecture, and we are still applying tremendous effort to understand interfaces in new material generations, with wide-bandgap materials being no exception. If anything, wide bandgap materials are more vulnerable to defect states purely due to...

The interest in novel carbonaceous materials with large effective surface areas, as well as high conductivity and stability, is growing due to the downsizing of electrical devices and the demand for new low-cost materials. For those applications it is necessary to find materials with high electrical conductivity like it is the case for graphene and nitrogen doped graphene. These nanostructures...

The progressive miniaturisation of feature sizes in microelectronic devices has increased the probability of higher local power densities and consequently temperatures. Complex multi-layered metallisation schemes, often implemented in devices, can suffer from detrimental interdiffusion phenomena between adjacent layers, compromising device reliability, when subjected to such severe local...

Operando characterization of working catalysts, requiring the simultaneous measurement of catalytic performance, is crucial to identify the relevant catalyst structure/composition and how molecules interact with surfaces/interfaces. The two examples, covering nanoparticles, thin films and meso-scale aggregates, bridge the "materials and pressure gaps".
i) Area-averaging operando spectroscopy:...

The increasing global energy demand has fuelled considerable effort into improving upon current energy storage technologies to keep in step with this demand. Improving current energy storage technologies, such as lithium ion batteries (LIBs), requires insight and understanding of the fundamentals of their operation. A key component of LIBs is the solid-electrolyte interphase (SEI), which...

Deposition of thin protective films on the cathode surface is an efficient approach to overcome interfacial degradation processes and control ionic mobility across the interface. An essential requirement of a good coating layer is that in addition to surface passivation, it will enable unimpeded ion transport between the electrode and electrolyte. To date, the rational design of such...

From single-crystal model catalysts to nanoparticle catalysts deposited on a substrate: Operando characterization of catalytic materials has become an important research field to unravel the complexity of catalytic reactions on the atomic level at the gas-surface interface. To bridge the pressure gap between industrial applications and surface science research , an interest in...

Understanding the mechanisms behind chemical transformations is key to developing improved catalytic systems. In this context, operando spectroscopy has contributed significantly to advance our molecular view of many reactions at heart of the chemical industry. Here we show the application of complementary spectroscopic techniques to elucidate the mechanism of a reaction that has always...

Polarization-dependent sum-frequency generation (SFG) spectroscopy was applied to study the adsorption of carbon monoxide (CO) on the annealed and sputtered Ir(111) single crystal surfaces at various CO coverages [1]. Coverage was adjusted by varying the substrate temperature (300−575 K) and/or gas pressure (10−7 to 1.0 mbar). The cleanliness of Ir(111) was confirmed by Auger electron...

Methanol has the potential to become an important energy vector. The so-called "methanol economy" is essentially a carbon-neutral cycle consisting of two groups of reactions: Methanol synthesis from a mixture of CO, CO2, and H2, and methanol-to-hydrogen conversion reaction. Latter includes methanol decomposition (or dry dehydrogenation), partial oxidation, steam reforming, and autothermal...

Organic semiconductors are highly relevant materials concerning future electronic devices due to their advantageous properties like high charge injection ability. Thin layers of acenes on metals like copper or silver are discussed to induce complex electronic characteristics, depending on factors like substrate metal workfunction and molecule adsorbate electron affinity. In this study the...

The ability to study the solid/liquid interface in situ is essential to gain fundamental understanding of electrochemical processes. A poor understanding of surface chemical processes at electrodes is a key bottleneck in the development of many energy technologies -e.g. alternative battery technologies or water splitting catalysts. X-Ray Photoelectron Spectroscopy (XPS) is one of the most...

The electrochemical deposition and growth of nanostructured platinum films was investigated in operando with Grazing Incidence Small Angle X-ray Scattering (GISAXS) - a non-destructive surface-sensitive technique for structure determination in the nm-regime. The deposition of the films was templated using hexagonal ($H_1$) lyotropic liquid crystalline phases of non-ionic surfactants, a...

Colloidal nanocrystals (NCs) offer the opportunity for realising novel solid state materials with tailored functionalities. By chemical synthesis, a large variety of semiconducting and metallic NCs can be realised [1] that can be used as efficient light emitters [1, 2] or in novel batteries designs [3].

Especially the inner structure and the shape of semiconducting core/shell NCs determine...

Recently the SMA and FeSMA field has attracted interest for solid state refrigeration applications. Among NiMnGa-based quaternary systems, NiMnGaCu exhibits an interesting giant magnetocaloric effect thanks to the temperature overlapping of magnetic transition and thermoelastic martensitic transformation (TMT), in particular for compositions with about 6at% Cu content. In the present work in...

For long steel products, the microstructure components have a major importance to guarantee good mechanical properties. This paper will discuss how the type of bainite microstructure can affect the impact energy. For this purpose, two bainitic steel grades with different impact energy were compared in term of microstructure. Both steel microstructures was investigated in terms of morphology,...

The functional properties of materials are increasingly controlled and tuned through structural or chemical architectures whose engineering takes place at the nano or even atomic level. This enables emergent properties relying on the interplay between charge, spin or local atomic-scale chemistry. A particularly powerful means of characterization of these physico-chemical effects lies within a...

Indium Selenide (InSe) is a remarkable two-dimensional quantum material whose characteristic properties include a bandgap that increases with fewer layers and a high controllability of p- and n-type doping. Furthermore, its bandgap can lie in the near infrared region, depending on the specific crystalline phase adopted. Indium Selenide is known to crystallize in either the β(2H)-, γ(3R)- or...

Within layered (two-dimensional) materials, the stacking sequences (polytypes) and physical properties of the materials are deeply intertwined. Tailoring specific stacking sequences thus provides a powerful handle in the design of nanostructures based on layered materials exhibiting novel physical properties. In this context, Transition-Metal Dichalcogenides (TMDs) based nanostructures...

Industrial catalysts belong to a class of functional materials that play an important role in the sustainable use of natural resources. For the development of improved catalysts, it is of crucial importance to gain atomistic insights about the structure-function relationship. Decades of research in catalysis have demonstrated the difficulty of this task. Challenges are related to the fact that...

The controlled introduction of impurities or defects within the lattice of 2D materials is a promising strategy for tailoring their properties. In this context, advanced microscopy techniques such as aberration-corrected scanning transmission electron microscopy (STEM) are able to characterize low-dimensional structures by resolving every atom, enabling the assignment of atomic bonding and...

In this work, we report the segregation-driven in situ generation
of Ag NWs on the surface of a Ag2WO4 (AWO) nanorod (NR) under
electron beam irradiation in an aberration corrected-TEM
(AC-TEM). We adopted AWO as the starting material because
previous studies have demonstrated Ag surface segregation and
the formation of Ag NPs on the oxide support under plasma or
electron beam...

We report for the first time the trapping of few-atom indium (In) clusters on substitutional silicon (Si) dopant atoms in the graphene lattice. Here, indium was evaporated onto suspended monolayer graphene (that intrinsically includes a small fraction of substitutional Si heteroatoms) using a custom-built preparation chamber (base pressure ~10-9 mbar) directly coupled to an atomic resolution...

Understanding the functional properties of novel nanomaterials demands and exhaustive characterization effort based on state-of-the-art complementary techniques. This is important for those nanomaterials where different shape-morphology configurations bring in an interplay between bulk properties and surface- and edge- induced effects. In this context, transition metal dichalcogenides (TMD)...

Since the discovery of 2D materials almost two decades ago, the family of atomically thin materials has grown immensely and includes now not only semi-metallic graphene but also semi-conducting and insulating representatives. The ability to draw from a set of materials with such diverse properties is highly beneficial in the development of new applications. Combining two or more 2D materials...

While S/TEM imaging methods and characterization techniques give insights on specimens, acquired images intrinsically represent a limited area (due to S/TEMs being high resolution instruments) with scarce statistical input. When nanoscale statistical data is required, this is achieved through manually acquiring multiple S/TEM (spectrum) images and processing them individually, which is not an...

Here we present studies on the growth of metals on suspended two-dimensional materials. Two-dimensional suspended monolayer substrates are imaged at the atomic scale, using a scanning transmission electron microscope, and deposited with metals using physical vapour deposition. Ubiquitous surface contamination is removed from the substrate on a 100 micrometre scale before the deposition, using...

Energy devices are commonly assembled from multiple functional components. To gain fundamental understanding of the microstructure-property relations between individual components, their degradation and failure mechanisms and to enable characterization/optimization cycles through transmission electron microscopy (TEM), it is desirable to prepare electron transparent cross sections of entire...

New functional materials combining stability, resistance to degradation, and efficiency with reasonable cost and ease of synthesis are crucial for their use in renewable energy applications. In catalysis, active metal nanoparticles dispersed on oxide surfaces are of fundamental interest to overcome the use of bulk noble metals. However, these bear the substantial limitations of the...

Dynamic surface modification of suspended graphene at high temperature was directly observed with in-situ scanning transmission electron microscope (STEM) measurement. The suspended graphene devices were prepared on top of the SiN membrane with hole substrate so that STEM observation was conducted under Joule heating processes. Current-voltage characteristics of suspended graphene devices...

Diamond and graphene are carbon allotropes with starkly different electronic properties. Combining them into graphene-on-diamond heterostructures provides new perspectives for devices that will benefit from these complementary properties. Graphitization, in particular mediated by a metal catalyst, is a promising synthesis route. In the present work, nickel-catalysed graphitization of single...

The water-processable nanoparticles (WPNP) assembled by hydrophobic conjugate polymers represent a new technology that finds application wide range of scientific filed, we focused on the organic photovoltaics (OPVs). In order to obtain a water-stable suspension of WPNPs, we selected four amphiphilic low band gap (LBG) rod-coil block copolymers (BCPs) composed of a rigid hydrophobic p-type...

The use of superconducting thin films on copper are proven technology for application in superconducting radio frequency (SRF) cavities, with Nb-coated cavities already in use at both the LEP and LHC at CERN. NbN is a candidate material for multilayer (ML), superconductor-insulator-superconductor (SIS) film structures which are reported to improve superconducting properties further. NbN offers...

The development of strong yet light fiber reinforced polymer (FRP) structures has attracted increased attention over the past few years. Epoxy foaming systems as core materials for carbon or glass fiber reinforced structures (CFRPs or GFRPs) find applications as primary or secondary structures in transportation, sports, and energy fields. Significant efforts have concentrated in increasing the...

Porphyrins and metalloporphyrins are versatile molecules, which offer a large variability of their properties due to the possibility to attach different ligands or metal atoms to the porphyrin macrocycle. The surface-confined self-metalation reaction describes the replacement of two aminic protons in the macrocycle of the porphyrin molecule by a metal atom of the substrate. This reaction was...

High resolution AFM with CO terminated probing tip is a valuable tool to determine the structural properties of molecular assemblies. In combination with on-surface chemistry rather complex 2d networks, ribbons or nanowires can be grown. In particular, graphene nanoribbons were succssfully grown and nano-friction experiments performed [1]. In a second stage, porous N-doped GNRs were grown and...

Nanostructuring of surfaces and subsequently tuning its properties is an important toolkit in nanoscience and surface physics. The formation of nano-hillocks and ion-tracks, induced by slow highly charged ions and swift heavy ions, respectively, were found to be mediated by a strong coupling of electronic excitations to lattice heating. In order to compare to previous results with slow highly...

The Ti49.2Ni50.8 alloy has a bcc lattice ordered according to the B2 type and a phase enriched with nickel Ti2Ni, was chosen as the research material. Thermal cycling of samples in a free state in various initial states was carried out by sequential immersion of the samples in liquid nitrogen, which is obviously lower than the temperature Ms of the direct transformation, followed by heating to...

Solid-liquid interfaces play a central role in a variety of chemical process including electrochemistry, electrolysis, and catalysis. They are at the heart of modern devices such as batteries, fuel cells, supercapacitors, and electrocatalytic reactors. The electrical double layer (EDL) which forms at the solid-electrolyte interface, plays a key role in moderating these processes. Due to the...

Scattering-type Scanning Near-field Optical Microscopy (s-SNOM) is a scanning probe approach to optical microscopy and spectroscopy bypassing the ubiquitous diffraction limit of light to achieve a spatial resolution. s-SNOM employs the strong confinement of light at the apex of a sharp metallic AFM tip to create a nanoscale optical hot-spot. Analyzing the scattered light from the tip enables...