Article
Engineering, Mechanical
Deepak Sharma, I. V. Singh, Jalaj Kumar
Summary: A computational framework is proposed to predict the microstructure sensitive mechanical behavior of polycrystalline materials, including fatigue crack initiation life and anisotropic deformation behavior. The framework generates 3D microstructural RVEs using Laguerre tessellation technique in Abaqus software. This methodology effectively models the complex geometry of grains and interfaces in 3D polycrystalline microstructures which is otherwise challenging. The predictions of fatigue crack initiation lives and anisotropic deformation behavior have shown good agreement with experimental data.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Willian G. Nunes, Aline M. Pascon, Bruno Freitas, Lindomar G. De Sousa, Debora Franco, Hudson Zanin, Leonardo M. Da Silva
Summary: A double-channel transmission line impedance model was used to investigate the charge transport characteristics in supercapacitors. The study found anomalies in the ionic and electronic transports during the decoration process of carbon-based electrical double-layer capacitors. The impedance model adequately described the charge storage and transport at the interface.
Article
Physics, Applied
M. Q. Hoang, M. Q. Nguyen, T. T. N. Vu, G. Teyssedre, S. Le Roy
Summary: The study developed a charge transport model that takes into account surface roughness. Simulation results show that surface roughness has a significant impact on the net space charge behavior.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Materials Science, Ceramics
Zhaowei Liang, Sheng'an Yang, Haishan Wang, Yule Li, Junfeng Li, Baokang Hou, Junhong Li, Jie Wang, Liang Wu, Hui Zhang, Qingming Chen, Ji Ma
Summary: This study investigates the effects of sintering temperature, vanadium addition, and vanadium addition route on the structure, morphology, and electrical transport properties of LCMO. The results show that higher sintering temperature and vanadium addition can improve the temperature coefficient of resistance (TCR) and promote the infrared detect application of LCMO.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
Julie Euvrard, Oki Gunawan, Antoine Kahn, Barry P. Rand
Summary: This study investigates the interplay between structural order and transport in organic semiconductors and reveals that transport in polycrystalline orthorhombic rubrene is limited by energy barriers at grain boundaries, with a gradual transition from band-like to hopping transport with increasing disorder.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Applied
Govindasamy Sathiyan, Haoxin Wang, Cheng Chen, Yawei Miao, Mengde Zhai, Ming Cheng
Summary: Perovskite solar cells (PSCs) have attracted significant attention in photovoltaic technologies due to their desirable properties. Fluorine substitution in organic materials is widely used to enhance the performance and stability of PSCs. This review discusses the effects of fluorine substitution in different layers of PSCs and its chemical interactions with the perovskite layer.
Article
Chemistry, Multidisciplinary
Pooja Bhatt, Kuljeet Kaur, Jino George
Summary: Recent experiments show that material properties like charge transport can be controlled by coupling to a vacuum electromagnetic field. The study found that in strongly coupled WS2, electron mobility is enhanced over 50 times at room temperature, and the I-on/I-off ratio of the device increases by 2 orders of magnitude without chemical modification of the active layer. These results suggest a promising way of modifying electronic properties by strong light-matter interaction.
Article
Chemistry, Physical
Adrian Olejnik, Bartlomiej Dec, William A. Goddard, Robert Bogdanowicz
Summary: This study elucidates the mechanisms of charge transport involving hydrogen bonds in molecular junctions. The analysis shows that electron-donating hydroxyl groups in the aromatic linker facilitate electron transfer through hydrogen bonding, while electron-withdrawing carboxyl groups inhibit electron transfer. Moreover, slight variations in the geometry of hydrogen bonding lead to significant changes in energy level alignment and transmission mode positions, resulting in a switch from tunneling to hopping electron transport mechanisms.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Duncan W. MacLachlan, Vasilis Karamitros, Fionn P. E. Dunne
Summary: This paper proposes an engineering approach to the problem of fatigue crack initiation at the microstructural scale. The initiation of fatigue cracks is broken down into separate processes, and a fundamental approach to modelling these processes has been developed. The method successfully correlates with fatigue data for a specific material.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Chemistry, Multidisciplinary
Davide Stefani, Cunlan Guo, Luca Ornago, Damien Cabosart, Maria El Abbassi, Mordechai Sheves, David Cahen, Herre S. J. van der Zant
Summary: The study investigates charge transport across single short peptides using the MCBJ method, revealing that different peptide lengths and compositions lead to a wide range of conductance values. Short peptides with more rigidity exhibit lower conductance values, while longer and more flexible peptides show higher values.
Article
Nanoscience & Nanotechnology
Paula Gomez, Stamatis Georgakopoulos, Miriam Mas-Montoya, Jesus Cerda, Jose Perez, Enrique Orti, Juan Arago, David Curiel
Summary: Molecular organization is crucial in determining the intermolecular interactions that govern charge transport in organic semiconductors. By strategically inducing or preventing hydrogen bonding in pyrrole-based molecules, researchers demonstrated improved stability and thermal robustness, as well as enhanced charge transport properties.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
P. Bhuyan, N. Kota, D. Bairagi, S. Sahasrabudhe, S. Roy, S. Mandal
Summary: The corrosion response of the Al-Si alloy/SiC foam interpenetrating phase composite (IPC) was investigated. SiC foams with different pores per inch (PPI) index were used to fabricate the IPCs. The corrosion resistance deteriorated in all the IPCs except for 20PPIC due to the incorporation of the reinforcing phase, which resulted in the formation of a less disrupted passive film and restricted pit growth.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Mechanics
D. P. Bourne, M. Pearce, S. M. Roper
Summary: In this paper, a fast algorithm is introduced for generating periodic RVEs of polycrystalline materials. It utilizes the damped Newton method from semi-discrete optimal transport theory to create 3D periodic Laguerre tessellations with cells of specified volumes. By extending recent results in semi-discrete optimal transport theory to the periodic setting, the Hessian of the objective function required by the damped Newton method is derived. This algorithm can generate complex, polydisperse RVEs with up to 100,000 grains of given volumes in just a few minutes on a standard laptop.
MECHANICS RESEARCH COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Tomasz N. Koltunowicz, Karolina Czarnacka, Piotr Galaszkiewicz, Fadei F. Komarov, Maxim A. Makhavikou, Oleg Milchanin
Summary: This paper presents the results of AC electrical measurements of Zn-SiO2/Si nanocomposites obtained by ion implantation. The study found that the conductivity and dielectric constant of the samples changed after annealing, indicating that annealing has an effect on the material properties.
Review
Chemistry, Physical
Michael Van Erdewyk, Dakota B. Lorenz, Justin B. Sambur
Summary: In the late 1970s and early 1980s, researchers found that smooth crystals were necessary for high-efficiency photoelectrochemical solar cells based on TMDS. However, anecdotal observations hinted at performance variation among apparently smooth crystals. This mini-review article explores how spatially resolved photoelectrochemical techniques are solving the mystery of performance variation.
CURRENT OPINION IN ELECTROCHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Erdogan Celik, Pascal Cop, Rajendra S. Negi, Andrey Mazilkin, Yanjiao Ma, Philip Klement, Joerg Schoermann, Sangam Chatterjee, Torsten Brezesinski, Matthias T. Elm
Summary: This study investigates the design of mixed-conducting nanocomposites by surface modification using atomic layer deposition (ALD). It was found that the porosity of the nanocomposites has no effect on their charge-transport properties, while the thickness of the ceria layer plays an important role.
Article
Chemistry, Physical
Julian Zahnow, Michele Bastianello, Juergen Janek, Matthias T. Elm
Summary: In this study, the electrochemical transport processes of individual grains with and without a grain boundary in microcrystalline oxide thin films were characterized using a microelectrode approach. It was found that the conductivity of single grains increases with increasing oxygen partial pressure, while the conductivity of grains with a grain boundary remains constant. These results are important for understanding the contribution of grain boundaries and grain interiors to the conductivity of polycrystalline materials.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Soren L. Dreyer, Katja R. Kretschmer, Dordije Tripkovic, Andrey Mazilkin, Richard Chukwu, Raheleh Azmi, Pascal Hartmann, Matteo Bianchini, Torsten Brezesinski, Juergen Janek
Summary: This article presents a method to form a hybrid coating on the surface of layered oxide cathode materials, which prevents degradation primarily through a fluorine-scavenging effect and by reducing the formation of rock salt-type phases.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Physics, Condensed Matter
Janis K. Eckhardt, Philipp E. Risius, Michael Czerner, Christian Heiliger
Summary: Disorder effects in alloys are usually modeled by averaging various supercell calculations considering different positions of the alloy atoms. In this study, a new approach called the coherent potential approximation combined with the Korringa-Kohn-Rostoker Green's function method was used to describe the disorder effects in alloy systems of any composition. It was applied to simulate the (de-)intercalation of arbitrary amounts of lithium from the cathode active material.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Till Ortmann, Simon Burkhardt, Janis Kevin Eckhardt, Till Fuchs, Ziming Ding, Joachim Sann, Marcus Rohnke, Qianli Ma, Frank Tietz, Dina Fattakhova-Rohlfing, Christian Kuebel, Olivier Guillon, Christian Heiliger, Juergen Janek
Summary: In recent years, reversible alkali metal anodes using solid electrolytes have been explored to increase the energy density of next-generation batteries. Na3.4Zr2Si2.4P0.6O12 has demonstrated potential as a solid electrolyte for solid-state sodium batteries due to its high ionic conductivity and stability with sodium metal. Analysis techniques such as impedance analysis, X-ray photoelectron spectroscopy, and transmission electron microscopy have revealed the formation of a stable interphase at the Na|Na3.4Zr2Si2.4P0.6O12 interface. The study provides valuable insights into the evaluation of sodium metal anode performance in solid-state batteries.
ADVANCED ENERGY MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Julius K. Dinter, Jurek Lange, Detlev M. Hofmann, J. Fabian Plaza Fernandez, Angel Post, Sangam Chatterjee, Matthias T. Elm, Peter J. Klar
Summary: Mayenite [Ca24Al28O64](4+)(2O(2-)) is a nanoporous compound with tunable electronic properties. The charge transport mechanisms and their variation with the degree of reduction x in the [Ca24Al28O64](4+)(2O(2-))((1-x))(4e(-))(x) system are still not fully understood. In this study, Hall-measurements and electron paramagnetic resonance (EPR) spectroscopy were used to characterize a series of polycrystalline [Ca24Al28O64](4+)(2O(2-))((1-x))(4e(-))(x) samples with different x, providing detailed insight into the electronic properties of the material.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Janis K. Eckhardt, Till Fuchs, Simon Burkhardt, Peter J. Klar, Juergen Janek, Christian Heiliger
Summary: Impedance spectroscopy is used to study solid-state batteries and analyze their charge transport and structural features. The impedance spectrum includes signals from the solid electrolyte and processes at the electrode interfaces. This study focuses on metal anodes and uses a 3D electric network model to analyze their impedance variations under different conditions. The study provides a method for experimentalists to identify impedance contributions from different interface effects and proposes a standard procedure for analysis.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Spectroscopy
Hannes Hergert, Matthias T. Elm, Peter J. Klar
Summary: We evaluate Raman spectroscopy as a fast and non-invasive method for mapping charge carrier density and carrier mobility in inhomogeneously doped 4H-SiC. A comparison between magneto-transport and Raman measurements of N-doped 4H-SiC reveals deviations in the extracted transport parameters, suggesting the need for an improved analysis model. By employing a three-band transport model, it is confirmed that only the free charge carriers in the conduction band contribute to the observed Raman signal.
JOURNAL OF RAMAN SPECTROSCOPY
(2023)
Article
Chemistry, Multidisciplinary
Hendrik Hemmelmann, Raffael Ruess, Philip Klement, Joerg Schoermann, Sangam Chatterjee, Joachim Sann, Matthias T. Elm
Summary: Depositing ultrathin oxide coatings has been proven an effective method to stabilize the surface of LiNixCoyMnzO2 active cathode material in lithium-ion batteries. While an aluminum oxide coating improves long-term cycling stability, a cerium oxide coating performs even worse than uncoated counterparts. X-ray photoelectron spectroscopy analysis reveals that both coatings are fluorinated upon contact with liquid electrolyte. The fluorinated aluminum oxide coating remains stable during cycling, leading to improved cell performance, while the fluorinated cerium oxide coating undergoes chemical composition changes and facilitates corrosion of the cathode material.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Janis K. Eckhardt, Sascha Kremer, Till Fuchs, Philip Minnmann, Johannes Schubert, Simon Burkhardt, Matthias T. Elm, Peter J. Klar, Christian Heiliger, Ju''rgen Janek
Summary: This study investigates the effects of microstructure on the material-specific properties of garnet-type Li7La3Zr2O12 ceramics. By employing a combinatorial approach of structural analysis and three-dimensional transport modeling, the researchers found that variations in grain size and porosity can lead to uncertainties of up to 150% in the derived transport parameters. Understanding the influence of microstructure on experimental results is crucial for improving the reproducibility and comparability of research findings.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Janis K. Eckhardt, Christian Heiliger, Matthias T. Elm
Summary: Ordered mesoporous oxides with their unique architecture have shown potential in various electrochemical applications such as gas sensing and energy storage. The high accessibility of the internal surface allows for tailoring of their electrochemical properties, resulting in superior performance compared to other materials. However, reliable electrochemical characterization is hindered by the complex interplay between nanocrystalline grains, grain boundaries, and the pore framework. A 3D electric network model was used to investigate the impact of the pore structure on the electrical transport properties of mesoporous thin films. An empirical expression was derived that allows for the determination of the material-specific conductivity with less than 8% error.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Janik Luechtefeld, Hendrik Hemmelmann, Susanne Wachs, Christopher Behling, Karl J. J. Mayrhofer, Matthias T. Elm, Balazs Berkes
Summary: The dissolution of cathode active material is a major issue in battery aging. In this study, the potential-dependent transition metal dissolution from lithium-ion battery cathodes was investigated using an electrochemical flow cell and inductively coupled plasma mass spectrometry. The results showed that thin-film LiCoO2 cathodes exhibited uniform dissolution, while commercial composite cathode tapes had lower relative dissolution. Furthermore, the second cycle was found to have the highest dissolution.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Nils Neugebauer, Yi Wang, Matthias T. Elm, Detlev M. Hofmann, Christian Heiliger, Xingchen Ye, Peter J. Klar
Summary: This paper investigates the two-dimensional monolayer structures of magnetic nanoparticles on silicon substrates and finds that there is a distance-dependent dipolar interaction between the nanoparticles, which affects the collective response of the corresponding mesocrystals. Experimental and theoretical analysis reveals that the magnetization and magnetocrystalline anisotropy of the nanoparticles are reduced compared to their bulk values.
