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

Controlling magnetic properties by tuning carrier concentration is a key feature of diluted ferromagnetic semiconductors, giving possibilities for multifunctional spintronic devices. Here, the evidence of the long-range magnetic order in V-doped WSe2 semiconductors will be presented. The magnetic domains of the long-range ferromagnetic order are observed by magnetic force microscopy at room...

In the quantum Hall (QH) regime, charge carriers flow in one dimensional quantum Hall edge channels (QHECs) and are topologically protected against backscattering. Due to its intrinsic two-dimensionality and the massless nature of its charge carriers, graphene constitutes a fascinating platform for studying QH effect. However, graphene edges are known to strongly harm the topological...

Studying local variations in the Peltier [1] or Seebeck coefficient of materials is important to optimise their thermoelectric properties and to enable applications like single-material thermocouples [2]. Yet most global experiments overlook spatial divergences in the signal and the role of local variation and the internal structure. Here, we developed Scanning Thermal Gate Microscopy (STGM),...

We have recently shown that proximity with a high-temperature superconductor induces unconventional superconducting correlations in graphene[1]. We will here talk about recent experiments demonstrating [2] that those correlations propagate hundreds of nanometers, allowing for the unique observation of d-wave Andreev-pair interferences in YBCO-graphene devices that behave as a Fabry-Perot...

We report recent work in DNA translocation in 2D nanoslit. 2D nanoslit devices, where two crystals with atomically flat surfaces are separated by only a few nanometers, have attracted considerable attention because their tunable control over the confinement allows for the discovery of unusual transport behavior of gas, water, and ions. Here, the passage of double-stranded DNA molecules is...

Electron-transfer reactions are ubiquitous in chemistry, however, there are still gaps in the fundamental understanding of electron transfer at the molecular level, particularly the degree to which the nuclear dynamics that accompany the process straddle the quantum-classical boundary. We use graphene-based single-molecule transistors [1] to study the mechanism of electron transfer over a wide...

Significant advances in the synthesis of low-dimensional materials with unique and tuneable electrical, optical and magnetic properties have led to discoveries ranging from single-photon sources to the observation of Majorana states. However, the lack of ability to precisely integrate individual nanomaterials into devices at scale limits their technological application. In this talk we will...

Graphene is a monolayer of sp2-bonded carbon atoms tightly packed into a two-dimensional honeycomb lattice. This material is very intensively studied nowadays due to its extraordinary properties. While graphene is nonmagnetic in itself, experimental observations show that magnetism can be induced by introduction of impurities, boundaries or defects. The properties of graphene can also be...

In the last years 2D materials have attracted a huge attention for spintronics thanks to the amazing properties that arise when thickness approaches the single layer level and thanks to the large number of functionalities that they offer. The recent introduction of 2D materials in magnetic tunnel junctions (2D-MTJs) offers very promising properties such as atomically defined interfaces, spin...

Spintronics has opened a new paradigm through the use of the spin variable as the vector of information and has been largely applied from hard drives read-heads to the STT-MRAMs. While very recent, the introduction of 2D materials in Magnetic Tunnel Junctions (MTJs) has already shown some promising properties (atomic thickness control, diffusion barrier, spin filtering…)[1]. Graphene and the...

Graphene's potential for spintronic applications has gained a lot of attention due to its gate tunability, high mobility and low intrinsic spin orbit coupling (SOC) strength. In recent works, researchers exploited these properties to propagate the electron spin up to 30 µm [1]. However, long communication...

Molecular spintronics involving spin-state switching in first-row transition-metal organic complexes has seen rapid progress in recent decades. In particular, molecular complexes hosting Fe, Co, Ni, or Mn ions can exhibit multiple spin-states depending on a subtle balance between molecular ligand field and Coulomb interaction. However, integration of such molecules into a spin-switch device...

Optical modulators are fundamental building blocks in a large variety of modern technological applications: phase, frequency, amplitude and polarization modulators such as electro-optic (EOM) and acousto-optic modulators (AOM) are widely used in fibre optic communication systems, ultrafast spectroscopy, metrology, active Q switching/mode locking of lasers and quantum information. The research...

2D crystals like graphene and transition metal dichalcogenides are stable because of their fully saturated in-plane covalent bonds. Another way to stabilize crystals in a low-dimensional conformation is to restrict the inclusion of atoms at the crystal edges via kinetic barriers. Such systems that include for instance metal nanowires grown inside carbon nanotubes and molecular crystal in...

Noble gas clusters trapped between two or more graphene layers form two-dimensional noble gas crystallites that are directly observable in an atomically resolved scanning transmission electron microscope (STEM). These otherwise inert atoms appear in both solid- and liquid-like phases, and in our experiments the clusters exhibit size-dependent, electron-beam driven dynamics that include, for...

Understanding the mechanisms governing large scale defect and contaminants in CVD grown 2D materials on transition metal catalysts and their transfer to target substrates are of crucial importance when creating high performance devices. Contamination introduced during transfer and handling is one of the most common factors why devices underperform. The interface between 2D layers in a...

Two-dimensional (2D) antimony (Sb, "antimonene") recently attracted interest due to peculiar electronic properties and suitability as anode material in batteries. Sb however exhibits a large polymorphic/allotropic structural diversity, which is also influenced by the Sb's support. Thus understanding Sb heterostructure formation is key in 2D Sb integration. Particularly 2D Sb/graphene...

One of the driving forces of the ongoing nanotechnology revolution is the ever-improving ability to understand and control the properties of quantum matter down to the atomic scale. Key drivers in this revolution are quantum materials, such as the two-dimensional (2D) materials of the transition metal dichalcogenide (TMD) family. The realization of novel TMD-based devices relies heavily on...

Topological semimetals are candidate hosts of interesting types of low-energy quasiparticles such as type-I and type-II Dirac and Weyl fermions. A type-III crossing point [1-3] emerges as a theoretical possibility exactly at the border between type-I and II, characterized by a line-like Fermi surface and a flat energy dispersion. We theoretically predict [4] that HfTe2 and ZrTe2 transition...

Doping is fundamental to tune the properties of 2D transition metal dichalcogenides for their future integration in the CMOS architecture, hence achieving substitutional doping during growth is of paramount importance. N-type monolayer WSe2 is often exfoliated from bulk crystals and a procedure to directly dope the material is yet to be established. Here, we demonstrate the synthesis of...

The controllable, reproducible and scalable growth of graphene and related 2D materials remains the foremost challenge for both research and any technologies exploiting their unique properties. While chemical vapour deposition (CVD) has become the most widespread method for 2D material film growth, even basic process parameters remain not well understood due to the manifold, complex parameter...

Heavier group-IV element bismuth ultrathin films exhibit numerous interesting properties such as strong SOC, high carrier mobility at RT and large Fermi wavelength. These properties constitute Bi films as possible candidates for exploitation of dissipation-less spin channels for both electronics and spintronics applications.
Bi films on HfTe2/InAs(111) templates were grown by molecular beam...

Among various two-dimensional (2D) materials, molybdenum disulfide (MoS2) has received intensive interest owing to its unique physical, chemical, and mechanical properties. Being capable of synthesizing MoS2 nanostructures with controlled dimensions, manipulating, and assembling them to designated structures or locations could accelerate technical breakthroughs in their applications. Herein,...

The lack of a CMOS-compatible transfer process restricts the realization of large-scale-high-quality monolayer graphene (MLG) applications. Although wafer-scale single-crystal MLG films can be synthesized on epitaxially deposited single-crystal Cu(111) on c-plane sapphire (Al$_2$O$_3$) templates, the non-straightforward intercalation base transfer process becomes a bottleneck. Hence, an...

A promising application of porous graphene is that of membrane for gas separation. In the present work, we apply DFT approximations to calculate the energy barriers, and subsequently, we estimate the permeation of several molecular systems through pores in single-layer graphene. Our calculations are at the level of hybrid-meta GGA functionals. Several different kinds of pores were considered...

Two-dimensional Transition Metal Dichalcogenides (2D-TMDs) have been in the spotlight for the last two decades due to their potential impact in future electronics, thermal and chemical applications. By tuning their composition, number of layers and strain we can control mechanical strength, bandgap, charges mobility, and thermal conductivity. Among them, 2D-MoS2 is of particular interest for...

Wafer-scale monocrystalline two-dimensional (2D) materials can theoretically be grown on the basis of seamless coalescence of individual domains into a large single-crystal. However, the coalescence behavior of 2D materials is not sufficiently understood to be controlled and utilized in industrial production.
Building on our in situ studies of graphene and hexagonal boron nitride growth...

Graphene is a promising material for different applications due to its high surface area, conduc-tivity and possibility of chemical modification; but technical material production of greater quantities is yet difficult and expensive. Electrochemical exfoliation processes appear to be a viable solution to produce single-sheet to few-layered graphene oxide powder from graphite. Based on this...

The bottom-up approach provides almost endless possibilities toward the creation of molecular based materials with designs that can be tuned by learning-doing cycles using structural-functional correlations.
Curcuminoids (CCMoids) are small conjugated molecules increasingly studied in the fields of Nanoscience and Nanotechnology due to their straightforward synthesis and purification,...