Article
Chemistry, Physical
Qingxin Kang, Guofeng Wang, Qing Liu, Xiaochong Sui, Yongkang Liu, Yuqing Chen, Shuyi Luo, Zhenlun Li
Summary: Density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) were used to investigate the CrN oxidation mechanism. The results show that the (100) surface has the lowest surface energy, stable adsorption sites for oxygen molecules and atoms, and the formation of CreO bonds between O-p and Cr-d orbitals.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Multidisciplinary Sciences
Mengxi Wang, Jun Zhou, Xiaoguang Xu, Tanzhao Zhang, Zhiqiang Zhu, Zhixian Guo, Yibo Deng, Ming Yang, Kangkang Meng, Bin He, Jialiang Li, Guoqiang Yu, Tao Zhu, Ang Li, Xiaodong Han, Yong Jiang
Summary: In this study, an antiferromagnetic insulator-based heterostructure, NiO/Ta/Pt/Co/Pt, is proposed for spin polarization control. Zero-field magnetization switching can be achieved through modulation of the out-of-plane component of spin polarization at the NiO/Pt interface. The switching ratio can be effectively tuned by the substrates, offering a promising platform for energy-efficient spintronic devices.
NATURE COMMUNICATIONS
(2023)
Review
Chemistry, Multidisciplinary
Edward Ditler, Sandra Luber
Summary: Vibrational spectroscopy is an important experimental technique for characterizing molecules and materials, but the interpretation of experimental results can be challenging. Computational studies using molecular dynamics simulations provide a valuable tool for understanding and predicting experimental results. This review article summarizes the field of vibrational spectroscopy using first-principles molecular dynamics and highlights recent advances in simulation techniques.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Dushuo Feng, Zhong Shen, Yufei Xue, Zhihao Guan, Runhu Xiao, Changsheng Song
Summary: This study reveals the major features and deep physical mechanisms of a magnetic phase transition and magnetic anisotropy switching in monolayer CrTe2 and antiferromagnetic (AFM) skyrmions in bilayer CrTe(2) through first-principles calculations and micromagnetic simulations. It is found that a magnetic phase transition from stripy-type AFM to ferromagnetic (FM) order can be induced by applying a tensile strain of 3%. Moreover, the magnetic easy axis can be switched between in-plane and off-plane via adjusting the magnitude of strain. Additionally, a topologically protected bilayer AFM skyrmion is stabilized by a large Dzyaloshinskii-Moriya interaction (DMI) of 1.43 meV and a skyrmion lattice can be induced by a magnetic field of 6.9 T at 100 K. The bilayer AFM skyrmion, different from the monolayer magnetic skyrmion, is more promising in spintronic nanodevices owing to the suppressed skyrmion Hall effect.
Article
Chemistry, Multidisciplinary
Sascha Jahnigen, Katia Le Barbu-Debus, Regis Guillot, Rodolphe Vuilleumier, Anne Zehnacker
Summary: In this study, the effect of a twofold screw axis on the solid-state VCD spectrum was investigated using both experimental and theoretical analysis. It was found that the VCD spectrum can reflect the supramolecular chirality of the crystal.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Peng Gao, Xihao Chen, Jiwen Li, Yue Wang, Ya Liao, Shichang Liao, Guangyu Zhu, Yuebin Tan, Fuqiang Zhai
Summary: Density functional theory calculations were used to investigate the electronic structure and hydrogen storage performance of aluminum-doped g-CN material. The results showed that the doped aluminum atoms form chemical bonds and transfer partial charge with pyridinic nitrogen atoms, enabling polarization of H2 molecules and their adsorption. Each supercell can accommodate up to 24 H2 molecules, with a hydrogen storage capacity of 6.15 wt%. The study demonstrates the potential of aluminum-doped g-CN material for efficient hydrogen storage.
Article
Chemistry, Physical
Tatsuya Ishiyama
Summary: NE-AIMD simulations were used to study the vibrational energy relaxation path of excited non-hydrogen-bonded OH at an air/water interface. The simulations reproduced experimentally observed features, showing that relaxation time scales of free OH at the surface of pure water and isotopically diluted water are similar. It was found that both stretching vibrational coupling and bend-stretching combination band contribute to the relaxation path of free OH at the surface.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Davide Gambino, Oleksandr I. Malyi, Zhi Wang, Bjorn Alling, Alex Zunger
Summary: Describing the electronic and magnetic properties of compounds requires considering different spin configurations and lattice structures. The interplay between spin configuration and lattice structure is crucial in understanding quantum materials. However, there is limited understanding of the theory required to determine spin configurations at finite temperature.
Article
Multidisciplinary Sciences
Barbara Kirchner, Jan Blasius, Lars Esser, Werner Reckien
Summary: This study investigates two possible ways to perform spectroscopy calculations in complex situations for vibrational spectra prediction. The results show that the cluster-weighted approach is inferior to simulations in terms of computational cost but still reaches very good results.
ADVANCED THEORY AND SIMULATIONS
(2021)
Article
Chemistry, Physical
Dmitry A. Fedorov, Matthew J. Otten, Stephen K. Gray, Yuri Alexeev
Summary: The paper introduces a method for running AIMD simulations on NISQ-era quantum computers, utilizing numerical calculation of energy gradients and correlated sampling technique with additional classical computations. The method has been successfully demonstrated for the H2 molecule on IBM quantum devices, and shown to be valid for larger molecules using full configuration interaction wave functions as quantum hardware and noise mitigation techniques improve.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Multidisciplinary Sciences
Xingxu Yan, Chengyan Liu, Chaitanya A. Gadre, Lei Gu, Toshihiro Aoki, Tracy C. Lovejoy, Niklas Dellby, Ondrej L. Krivanek, Darrell G. Schlom, Ruqian Wu, Xiaoqing Pan
Summary: The study shows that space- and angle-resolved vibrational spectroscopy in a transmission electron microscope can map the vibrational spectra of individual crystal defects, revealing changes in energy and intensity of acoustic vibration modes restricted to a few nanometers around the defect. The capabilities of a state-of-the-art transmission electron microscope open the door to directly mapping phonon propagation around defects, offering valuable guidance for engineering the thermal properties of materials.
Article
Multidisciplinary Sciences
Feihong Chu, Xianlin Qu, Yongcai He, Wenling Li, Xiaoqing Chen, Zilong Zheng, Miao Yang, Xiaoning Ru, Fuguo Peng, Minghao Qu, Kun Zheng, Xixiang Xu, Hui Yan, Yongzhe Zhang
Summary: The authors design a hybrid interface by tuning the pyramid apex-angle to improve the interfacial morphology of c-Si/a-Si:H in silicon solar cells. This hybrid interface prevents both c-Si epitaxial growth and nanotwin formation, leading to improved interfacial morphology. This method can be widely applied to all silicon-based solar cells without any additional industrial preparation processes.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Anatoly B. B. Belonoshko, Grigory S. S. Smirnov
Summary: Iron is the main component of Earth's core and exoplanetary cores. The crystal structure of iron under extreme conditions of high pressure and temperature is still unknown. Experimental data and simulations have contradictory results regarding the stability of different phases of iron. By using large-scale ab initio molecular dynamics simulations, this study compared the properties of iron phases at experimental conditions to provide a potential explanation for the experimental observations.
Article
Materials Science, Multidisciplinary
Luke J. Wirth, Christopher Woodward, Amir A. Farajian
Summary: Advances in first principles methods are used to study the atom-vacancy exchanges near a screw dislocation in fcc Ni, revealing direction-dependent free energy profiles and temperature-dependent correlation effects. The dynamic approach shows intra-cell energy profile asymmetry related to dynamic geometry rearrangements. Despite absolute values of rate constants being similar, the HTST method generally underestimates rates by a factor of 2-5, partially explaining discrepancies between theoretical works and experiments in pipe diffusion diffusivities.
Article
Chemistry, Multidisciplinary
Yufeng Luo, Shihao Han, Rui Hu, Hongmei Yuan, Wenyan Jiao, Huijun Liu
Summary: In recent years, there has been significant interest in Janus monolayers due to their unique asymmetric structures and intriguing physical properties. However, little is known about the thermal stability of these two-dimensional systems. Through investigating the Janus monolayers SnXY (X, Y = O, S, Se) using molecular dynamics simulations, it was found that the system with higher thermal stability exhibits a smaller difference in the bond length of Sn-X and Sn-Y. Based on these findings, a simple rule was proposed to quickly predict the maximum stable temperature of Janus monolayers.
Article
Materials Science, Multidisciplinary
Zhixing Wu, Penghui Ding, Viktor Gueskine, Robert Boyd, Eric Daniel Glowacki, Magnus Oden, Xavier Crispin, Magnus Berggren, Emma M. Bjork, Mikhail Vagin
Summary: Electrocatalysis plays a crucial role in achieving sustainable chemical production using abundant resources and renewable energy. In this study, we developed an effective electrochemical method for producing hydrogen peroxide (H2O2) using only pure water and oxygen. Nickel (II) oxide (NiO) was used as the electrocatalyst for oxygen evolution reaction (OER) at the anode, while a conducting polymer poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) drove the oxygen reduction reaction (ORR) at the cathode to generate H2O2. The conversion efficiency of the H2O2 electrochemical refinery was limited by unbalanced ionic transport in the solid electrolyte, but optimization of operation conditions achieved an efficiency of 80%.
ENERGY & ENVIRONMENTAL MATERIALS
(2023)
Article
Chemistry, Physical
Tun-Wei Hsu, Grzegorz Greczynski, Robert Boyd, Szilard Kolozsvari, Peter Polcik, Magnus Oden
Summary: Titanium tungsten carbide (TiWC) coatings were deposited using a combined high-power impulse and dc magnetron co-sputtering technique. The deposition phase involved heavy ion irradiation instead of external heating. The coating structures were established using titanium carbide targets in dc magnetron mode and tungsten carbide targets in high-power impulse mode. Varying the peak target current density (JT) controlled the intensity of W+ ion flux, which affected the film properties. The hybrid process resulted in dense TiWC coatings with a hardness above 30 GPa, comparable to films deposited using dc magnetron sputtering with external heating. The relative energy consumption was reduced by 77% compared to high-temperature dc magnetron sputtering.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Bin Zhang, Johan Klarbring, Fuxiang Ji, Sergei Simak, Igor A. Abrikosov, Feng Gao, Galyna Yu Rudko, Weimin M. Chen, Irina A. Buyanova
Summary: Phonon-phonon and electron/exciton-phonon coupling are found to play a vital role in the thermal, electronic, and optical properties of metal halide perovskites. Our study focuses on the evaluation of phonon anharmonicity and coupling between electronic and vibrational excitations in the novel material, Cs2NaFeCl6, through Raman measurements and theoretical calculations. The results highlight the significance of phonon-phonon and electron-phonon interactions in the electronic properties of Cs2NaFeCl6.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Henrik Levaemaeki, Florian Bock, Davide G. Sangiovanni, Lars J. S. Johnson, Ferenc Tasnadi, Rickard Armiento, Igor A. Abrikosov
Summary: Data-driven approaches are valuable for modern science and are being utilized in industrial R&D. This paper introduces the HADB database, which contains properties of chemically disordered hard-coating alloys. The technical implementations of the database infrastructure, including browse, query, retrieval, and API access through the OPTIMADE API, are presented to make the data findable, accessible, interoperable, and reusable (FAIR). Finally, the usefulness of the database is demonstrated by training a graph-based machine learning model to predict elastic properties of hard-coating alloys, with an average error of less than 6 GPa for out-of-sample alloys.
Article
Chemistry, Multidisciplinary
Dominique Laniel, Florian Trybel, Yuqing Yin, Timofey Fedotenko, Saiana Khandarkhaeva, Andrey Aslandukov, Georgios Aprilis, Alexei I. Abrikosov, Talha Bin Masood, Carlotta Giacobbe, Eleanor Lawrence Bright, Konstantin Glazyrin, Michael Hanfland, Jonathan Wright, Ingrid Hotz, Igor A. Abrikosov, Leonid Dubrovinsky, Natalia Dubrovinskaia
Summary: The recent high-pressure synthesis of pentazolate and the stabilization of the aromatic [N-5](-) anion at atmospheric pressure have significantly impacted nitrogen chemistry. The synthesis of the aromatic hexazine anion [N-6](4-) is presented in this study, achieved through the reaction of nitrogen and KN3 under high pressure and high temperature conditions. The complex structure of K9N56, consisting of 520 atoms per unit cell, was determined using synchrotron single-crystal X-ray diffraction and validated by density functional theory calculations. The observed hexazine anion [N-6](4-) was found to be planar and potentially aromatic.
Article
Nanoscience & Nanotechnology
J. Salamania, K. M. Calamba Kwick, D. G. Sangiovanni, F. Tasnadi, I. A. Abrikosov, L. Rogstrom, L. J. S. Johnson, M. Oden
Summary: The defect structures forming during high-temperature decomposition of Ti1-xAlxNy films were investigated through high-resolution scanning transmission electron microscopy. Two types of dislocations, misfit edge dislocations and a/6(112){111} partial dislocations, were found at the interface between TiN-rich and AlN-rich domains. The stacking fault energy associated with the partial dislocations decreases with increasing Al content, facilitating the phase transition of AlN-rich domains. Additionally, intersections of stacking faults were observed at the interface after annealing to 1100 degrees C, contributing to the hardening in Ti1-xAlxNy.
SCRIPTA MATERIALIA
(2023)
Article
Physics, Applied
Oscar Bulancea-Lindvall, Matthew T. Eiles, Nguyen Tien Son, Igor A. Abrikosov, Viktor Ivady
Summary: Paramagnetic defects and nuclear spins are the main causes of decoherence and spin relaxation in solid-state qubits. It is believed that depleting nuclear spins can enhance coherence time, but our study shows that excessive isotope purification can have a negative effect on qubits, especially for half-spin systems.
PHYSICAL REVIEW APPLIED
(2023)
Article
Materials Science, Multidisciplinary
Johan Klarbring, Utkarsh Singh, Sergei I. Simak, Igor A. Abrikosov
Summary: A family of magnetic halide double perovskites (HDPs) with potential applications in spintronics has been studied using advanced DFT-based methods. The effect of different parameters on the electronic and structural properties of Cs2AgFeCl6 and Cs2NaFeCl6 has been investigated. The results show that Cs2AgFeCl6 undergoes significant renormalization of its electronic band structure due to disordered magnetism.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Smita G. Rao, Boburjon Mukhamedov, Gyula Nagy, Eric N. Tseng, Rui Shu, Robert Boyd, Daniel Primetzhofer, Per O. A. Persson, Bjorn Alling, Igor A. Abrikosov, Arnaud le Febvrier, Per Eklund
Summary: This study investigates the effect of nitrogen content on phase formation in CrFeCoNi thin films using theoretical and experimental methods. The results show that when the nitrogen content is x<=0.22, the film stabilizes in a face-centered cubic structure, while for x>0.33, it stabilizes in a NaCl B1 structure. However, when the nitrogen content is an intermediate value of x=0.22, phase segregation occurs in the film grown at higher temperatures. These findings are important for understanding the phase formation mechanisms in multicomponent ceramics and for correlating mechanical properties with crystal structure in films.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Davide G. Sangiovanni, Antoine Kraych, Matous Mrovec, Janella Salamania, Magnus Oden, Ferenc Tasnadi, Igor A. Abrikosov
Summary: Understanding the competition between brittleness and plasticity in refractory ceramics is important for designing hard materials with enhanced fracture resistance. This study investigates the mechanisms responsible for brittleness and slip-induced plasticity in Ti-N systems through atomistic investigations and simulations. The results show that slip plasticity can be promoted by a reduced sharpness of the crack and/or the presence of anion vacancies. The study also suggests using the ideal tensile/shear strength ratio as a descriptor for ranking the ability of ceramics to blunt cracks via dislocation-mediated plasticity at finite temperatures.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Amanda Ehn, Bjoern Alling, Igor A. Abrikosov
Summary: The Fe0.64Ni0.36 alloy exhibits a low thermal expansion at ambient conditions, known as the invar effect. Applying pressure to other FexNi1-x alloys can induce low thermal expansion, even for Ni-rich compositions, which is called the pressure induced invar effect. In this study, we investigate the pressure induced invar effect for FexNi1-x alloys with x = 0.64, 0.50, 0.25 using supercell calculations and considering noncollinear magnetic states. We observe anomalies in the equation of states for all three compositions, which coincide with magnetic transitions from a ferromagnetic state to a complex magnetic state.
Article
Nanoscience & Nanotechnology
Joel Davidsson, Rohit Babar, Danial Shafizadeh, Ivan G. Ivanov, Viktor Ivady, Rickard Armiento, Igor A. Abrikosov
Summary: In this study, a defect database generated by automatic defect analysis and qualification (ADAQ) workflows is used to identify and analyze defects in 4H-SiC that contribute to previously unidentified magneto-optical signals. A carbon anti-site structure near the silicon vacancy is identified as the cause of these signals, and its energetic boundness is determined. Computational and experimental results show good agreement, demonstrating the effectiveness of using a high-throughput database for defect search in quantum applications.
Article
Materials Science, Multidisciplinary
C. N. Saunders, D. S. Kim, O. Hellman, H. L. Smith, N. J. Weadock, S. T. Omelchenko, G. E. Granroth, C. M. Bernal-Choban, S. H. Lohaus, D. L. Abernathy, B. Fultz
Summary: In this study, inelastic neutron scattering measurements were used to observe phonons in cuprite single crystal at different temperatures. The results showed that the temperature-dependent phonon behavior was predicted more accurately with anharmonic calculations than quasiharmonic calculations.
Article
Materials Science, Multidisciplinary
Alexander N. Rudenko, Swagata Acharya, Ferenc Tasnadi, Dimitar Pashov, Alena Ponomareva, Mark van Schilfgaarde, Igor A. Abrikosov, Mikhail Katsnelson
Summary: A systematic study comparing the electronic and optical properties of crystalline black nitrogen (BN) and black phosphorus (BP) reveals significant differences between the two materials. BN has a larger optical gap and shows transparency in the visible spectral region with highly anisotropic optical response. The reduced dielectric screening in BN enhances the effective Coulomb interaction.
