Article
Chemistry, Physical
Elena Voloshina, Yukun Jin, Yuriy Dedkov
Summary: The electronic structure of wide bandgap van der Waals antiferromagnetic material CoPS3 is studied using angle-resolved photoelectron spectroscopy at room temperature. The dispersion of the electronic states in the valence band is correctly described using spin-resolved band structure, indicating the importance of local electron-electron correlations and fluctuations for the description of electronic and magnetic properties of transition metal phosphorus trichalcogenides. This provides further insights for studying the electronic structure of CoPS3 and similar materials.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Yuriy Dedkov, Jiali Yang, Han Hu, Yichen Jin, Mouhui Yan, Yukun Jin, Junhao Zhou, Elena Voloshina
Summary: The experimental synthesis of graphene/ferromagnetic-Mn5Ge3/semiconducting-Ge heterostructures is achieved by intercalating Mn in the epitaxial graphene/Ge interfaces. The formed heterosystems show graphene in close contact with ferromagnetic Mn5Ge3, and the linear band dispersion around the Fermi level for the carriers in graphene is confirmed. These findings provide interesting prospects for the integration of graphene in modern semiconductor technology with possible implications for spintronics device fabrication.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Marc G. Cuxart, Daniele Perilli, Sena Toemekce, Joel Deyerling, Felix Haag, Matthias Muntwiler, Francesco Allegretti, Cristiana Di Valentin, Willi Auwaerter
Summary: This work demonstrates how naturally occurring moire' patterns in Ir(111)-supported graphene can template the formation of ordered arrays of boron species. Experimental and theoretical studies provide a comprehensive understanding of the distribution, bonding configurations, interfacial interaction, and impact on graphene's electronic structure. The results show that boron prefers to form small aggregates by inducing local bending of graphene.
Article
Nanoscience & Nanotechnology
Lama Khalil, Debora Pierucci, Emilio Velez-Fort, Jose Avila, Celine Vergnaud, Pavel Dudin, Fabrice Oehler, Julien Chaste, Matthieu Jamet, Emmanuel Lhuillier, Marco Pala, Abdelkarim Ouerghi
Summary: This study visualizes the presence of a flat band near the Fermi level in the van der Waals WSe2/MoSe2 heterobilayer and confirms the coexistence of different domains with arbitrary twist angles. The strong interlayer hybridization effects are observed, which are further confirmed by complementary micro-Raman spectroscopy measurements.
Article
Nanoscience & Nanotechnology
Giuseppe Meneghini, Marcel Reutzel, Stefan Mathias, Samuel Brem, Ermin Malic
Summary: Van der Waals heterostructures exhibit fascinating physics, and hybrid excitons in bilayers of transition metal dichalcogenides can be directly visualized using time- and angle-resolved photoemission spectroscopy.
Article
Chemistry, Physical
Antonio J. Martinez-Galera, Haojie Guo, Mariano D. Jimenez-Sanchez, Enrique G. Michel, Jose M. Gomez-Rodriguez
Summary: New opportunities for graphene engineering can be achieved by adjusting interfacial interaction in terms of d-band filling and geometry of the support. Growth of graphene on Rh(110) surfaces shows distinct stripe-like moire patterns and Dirac cones around the Fermi level. The analysis also reveals the existence of two levels of interfacial interaction strength and the presence of Dirac cones in band structures of different rotational domains, indicating potential for novel graphene-metal interfaces.
Article
Engineering, Environmental
Manel Bergaoui, Valadoula Deimede, Mohamed Khalfaoui
Summary: This study reports the adsorption behavior of two anionic dyes using a polymeric adsorbent. The results reveal a two-step adsorption mechanism and higher reactivity of one dye compared to the other. The study expands our understanding of the adsorption mechanism of dyes.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Chemistry, Physical
Felix Reichmann, Emilio Scalise, Andreas P. Becker, Emily V. S. Hofmann, Jaroslaw Dabrowski, Francesco Montalenti, Leo Miglio, Mattia Mulazzi, Wolfgang M. Klesse, Giovanni Capellini
Summary: The debate on whether the Ge(0 0 1) surface is conducting or semiconducting at room temperature continues, with new evidence suggesting it is conducting. Experimental and computational studies reveal a surface band above the valence band maximum at room temperature, providing insights into the electronic properties and surface reconstruction of Ge(0 0 1).
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Stanislav Campelj, Matic Pobreznik, Tomas Landovsky, Janez Kovac, Layla Martin-Samos, Vera Hamplova, Darja Lisjak
Summary: In this study, MNPs were successfully functionalized with CAT, GAL, CAF, and NDA at different pH values. The functionalized MNPs showed higher saturation magnetizations (M-s) compared to the starting material. XPS analyses confirmed the presence of Fe(III) ions on the surface, ruling out the formation of magnetite. DFT calculations demonstrated that the adsorption of catechols did not affect the M-s. The increase in the average size of the MNPs and the decrease in the fraction of the smallest MNPs explained the observed increase in M-s values.
Article
Chemistry, Multidisciplinary
Susanne Wolff, Niclas Tilgner, Florian Speck, Philip Schadlich, Fabian Goehler, Thomas Seyller
Summary: The intercalation of sulfur on the carbon-rich buffer layer on silicon carbide is investigated. Successful intercalation is confirmed by X-ray photoelectron spectroscopy and low-energy electron diffraction. Angle-resolved photoelectron spectroscopy reveals p-type doping in the intercalated samples. Partial intercalation is observed in some cases with non-intercalated sulfur remaining on top of the buffer layer. Further annealing leads to the migration of the non-intercalated sulfur under the buffer layer.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Physical
Kangli Wang, Thomas Vincent, Jean Baptiste Bouhiron, Stephane Pons, Dimitri Roditchev, Sabina Simon, Mikhail Fonin, Beate Paulus, Yuriy Dedkov, Sergio Vlaic, Elena Voloshina
Summary: The interaction strength between graphene and substrate is strongly affected by the composition and nature of an alloy, leading to significant differences in the electronic structure of monolayer graphene on different Co-Ir alloys. This is supported by ARPES data showing the disappearance and restoration of the Dirac cone under different conditions.
Article
Chemistry, Physical
Osamu Endo, Fumihiko Matsui, Wang-Jae Chun, Masashi Nakamura, Kenta Amemiya, Hiroyuki Ozaki
Summary: The size and structural properties of graphene grown on a Pt(111) substrate exposed to benzene vary with different substrate temperatures during exposure, playing a significant role in graphene growth.
Article
Chemistry, Physical
Dheryck Schwendler Cabeda, Guilherme Koszeniewski Rolim, Gabriel Vieira Soares, Antonio Marcos Helgueira de Andrade, Claudio Radtke
Summary: Sulfurization can be used as an alternative to chemical vapor deposition for obtaining WS2 layers with specific thickness. However, the efficiency of sulfurization and the timing of S introduction play a crucial role in determining the characteristics of WS2 layers.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Alessandro De Vita, Thao Thi Phuong Nguyen, Roberto Sant, Gian Marco Pierantozzi, Danila Amoroso, Chiara Bigi, Vincent Polewczyk, Giovanni Vinai, Loi T. Nguyen, Tai Kong, Jun Fujii, Ivana Vobornik, Nicholas B. Brookes, Giorgio Rossi, Robert J. Cava, Federico Mazzola, Kunihiko Yamauchi, Silvia Picozzi, Giancarlo Panaccione
Summary: This research investigates the ground state electronic properties of CrI3 and VI3 and reveals the stability of different electronic phases and the influence of dimensionality effects.
Article
Chemistry, Physical
Marcin Rosmus, Natalia Olszowska, Zbigniew Bukowski, Pawel Starowicz, Przemyslaw Piekarz, Andrzej Ptok
Summary: This paper conducts a complex analysis of the electronic band structure of LaAgSb2 using ARPES and theoretical studies, identifying nodal lines related to crystal symmetry and from the vanishing of spin-orbit splitting at the X-M-A-R plane.
Article
Materials Science, Multidisciplinary
Sandhya Sharma, Hafiz Muhammad Zeeshan, Mohammad Panahi, Yichen Jin, Mouhui Yan, Yukun Jin, Kexin Li, Patrick Zeller, Anna Efimenko, Anna Makarova, Dmitry Smirnov, Beate Paulus, Elena Voloshina, Yuriy Dedkov
Summary: This study investigates the interaction of high-quality transition metal trichalcogenides (TMTs) single crystals FePX3 (X: S, Se) with water molecules using near-edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS). It is found that the interaction between H2O and FePX3 is a physisorption nature at low temperatures and relatively small concentrations of water molecules, supported by DFT results. As the temperature of the FePX3 samples and the partial pressure of H2O increase, the interaction at the interface is determined by two competing processes – adsorption of molecules at high partial pressure of H2O and desorption of molecules due to increased surface mobility and the physisorption nature of interaction. The intensive XPS/NEXAFS experiments accompanied by DFT calculations provide new understanding on the interaction of H2O with the surface of TMTs, pointing to their stability and reactivity, which is important for their further applications in areas such as sensing and catalysis.
Article
Chemistry, Physical
Kexin Li, Mouhui Yan, Yukun Jin, Yichen Jin, Yefei Guo, Elena Voloshina, Yuriy Dedkov
Summary: The electronic structure of the alloyed transition-metal phosphorus trichalcogenide van der Waals Fe1-xNixPS3 compounds is studied. The Fe-and Ni-ions-derived electronic states are highly localized, leading to the description of the spectroscopic data as belonging simultaneously to Mott-Hubbard and charge-transfer insulators. These findings highlight the unique layered compounds Fe1-xNixPS3 with dual character, emphasizing their importance for understanding the functionality of this class of materials.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Yuriy Dedkov, Jiali Yang, Han Hu, Yichen Jin, Mouhui Yan, Yukun Jin, Junhao Zhou, Elena Voloshina
Summary: The experimental synthesis of graphene/ferromagnetic-Mn5Ge3/semiconducting-Ge heterostructures is achieved by intercalating Mn in the epitaxial graphene/Ge interfaces. The formed heterosystems show graphene in close contact with ferromagnetic Mn5Ge3, and the linear band dispersion around the Fermi level for the carriers in graphene is confirmed. These findings provide interesting prospects for the integration of graphene in modern semiconductor technology with possible implications for spintronics device fabrication.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Elena Voloshina, Yukun Jin, Yuriy Dedkov
Summary: The electronic structure of wide bandgap van der Waals antiferromagnetic material CoPS3 is studied using angle-resolved photoelectron spectroscopy at room temperature. The dispersion of the electronic states in the valence band is correctly described using spin-resolved band structure, indicating the importance of local electron-electron correlations and fluctuations for the description of electronic and magnetic properties of transition metal phosphorus trichalcogenides. This provides further insights for studying the electronic structure of CoPS3 and similar materials.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Mouhui Yan, Yichen Jin, Elena Voloshina, Yuriy Dedkov
Summary: Recently, layered antiferromagnetic materials with different magnetic orderings have attracted increasing attention. It has been found that these properties can be maintained even at the monolayer level, opening up great potential for (opto)spintronics and sensing applications. However, there is a lack of experimental results on electronic structure studies for these materials. In this study, the effects of electronic correlations in FexNiyPS3 layered van der Waals (vdW) alloys were investigated using angle-resolved photoelectron spectroscopy (ARPES) and DFT calculations. The results showed that the top of the valence band in FePS3 is formed by hybrid Fe 3d-S 3p states, while in NiPS3, it is of pure S 3p character. For the mixed Fe-Ni-based vdW alloy, the electronic structure is a combination of contributions from the parent compounds. These findings provide a clear understanding of the insulating state in the studied MPX3 materials and pave the way for their applications in different areas.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Nicole Yvonne Suss, Eva M. Heppke, Elena Voloshina, Lukas Schifferle, Sergey S. Lobanov, Sergio Speziale, Hans Josef Reichmann, Tim Kuellmey, Beate Paulus, Martin Lerch, Ilias Efthimiopoulos
Summary: Quaternary kesterite-type compounds have shown promise for solar cells. In this study, experimental and computational high-pressure investigations were conducted on Ag2ZnSnS4 and Ag2CdSnS4 compounds. The results reveal successive transformations and predict metallic character for the high-pressure phases of both materials.
Article
Chemistry, Multidisciplinary
Yuriy Dedkov, Junhao Zhou, Yefei Guo, Elena Voloshina
Summary: The growth of a high-quality complete graphene layer is successfully achieved for Ir(111) and Ru(0001) substrates using liquid ethanol as a precursor,which provides an easy, quick, and reproducible method to synthesize large-scale graphene on different metallic substrates.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Jiajun Dai, Kangli Wang, Elena Voloshina, Yuriy Dedkov, Beate Paulus
Summary: The state-of-the-art density functional theory approach was used to study the structural and electronic properties of MnPX3 monolayers and their catalytic performance towards water and hydrogen evolution reaction. The study found that defective structures exhibited higher adsorption energy and better catalytic performance compared to the pristine structures.
Article
Instruments & Instrumentation
Marina V. Il'ina, Soslan A. Khubezhov, Maria R. Polyvianova, Oleg I. Il'in, Yuriy Dedkov
Summary: The chemical composition and stoichiometry of nitrogen-doped multi-walled carbon nanotubes were studied using photoelectron spectroscopy. The focus was on the pyridine/pyrrole-like defects and their impact on the piezoelectric response efficiency, and the XPS method was used to quantify the concentration and type of nitrogen incorporation.
QUANTUM BEAM SCIENCE
(2023)
