Article
Chemistry, Multidisciplinary
Meena Kumari, Jisha Annie Abraham, Ramesh Sharma, Debidatta Behera, S. K. Mukherjee, Mostafa M. Salah, Murefah mana Al-Anazy, Mohammed S. Alqahtani
Summary: This study evaluates the structural, magnetic, electronic, elastic, vibrational, optical, thermodynamic, and thermoelectric properties of newly predicted quaternary LiZrCoX (X = Ge, Sn) Heusler compounds using ab initio techniques. The results show that these compounds have stable structures, dynamic stability, and good thermoelectric behavior, making them suitable for manufacturing thermoelectric and optoelectronic materials, as well as energy-harvesting equipment.
Article
Chemistry, Physical
Xun-Jian Hu, Yi Yang, Chunju Hou, Tong-Xiang Liang
Summary: Perovskite oxides are versatile materials with rich properties, and recent research has shown that freestanding two-dimensional structures down to the monolayer limit can be prepared. The study reveals that 2D perovskite oxides exhibit abnormal band-gap trends, with a gap value lower than the bulk limit, indicating the presence of an unusual quantum size effect. The electronic properties of 2D perovskite oxides evolve with dimension change, with termination-dependent thermodynamic stability and band splitting contributing to the abnormal trends.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Payal Saha, Bhargab Kakati, Purbajyoti Bhagowati, Munima B. Sahariah
Summary: This study investigates the impact of spin-orbit coupling (SOC) on the electronic and magnetic properties of Mn1.5PtSn compound using density functional theory. Regardless of SOC, ferrimagnetic configuration is found to be more stable at the ground state compared to ferromagnetic and antiferromagnetic configurations. The SOC affects the ground state energy of the compounds, and various analysis methods provide insights into the magnetic and electronic properties of the system. The stable ferrimagnetic configuration shows high spin polarization and low magnetocrystalline anisotropy energy, making it suitable for spin-transfer-torque-based device applications like magnetic recording heads.
Article
Materials Science, Multidisciplinary
Lu Wu, Vasyl O. Kharchenko, Dmitrii O. Kharchenko, Rongjian Pan
Summary: The structural and energetic properties of Zr-Sn, Zr-Nb, and Nb-Sn binary alloys were studied using density functional theory, analyzing the behavior of different alloying additions in a host matrix and discussing the stability of various phases with different concentrations of alloying elements. The binding vacancy-impurity energy was calculated, and the ability of different impurities to trap single vacancies in different alloys was discussed in detail.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Songge Yang, Guangchen Liu, Yu Zhong
Summary: The stability and electronic properties of five compounds in the LK-99 family were investigated through experimental and theoretical calculations. The results show the presence of isolated flat bands near the Fermi level in Cu-substituted LK-99 compounds, and significant lattice changes were observed. Despite higher electronic conductivity, the Cu-substituted LK-99 compounds still fall short of the conductivity levels observed in metals or advanced oxide conductors.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Cheng-Yu Liu, Yu-Yun Liu, Su-Hua Chen, Sinn-Wen Chen, Adam Debski, Wladyslaw Gasior, Wojciech Gierlotka
Summary: A recent study has proposed a thermodynamic model for the binary Sb-Te system based on experimental and computational data. The obtained thermodynamic parameters have shown good reproducibility, providing a reference for future modeling of higher-ordered systems.
JOURNAL OF MATERIALS RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
M. Tyunina, J. Levoska, O. Pacherova, T. Kocourek, A. Dejneka
Summary: Oxygen vacancies have unique impacts on lattice strain in epitaxial films of ABO(3) perovskite oxides, leading to increased inhomogeneity of lattice strain under external stress.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Hanh Thi Thu Tran, Phi Minh Nguyen, Hoa Van Nguyen, Tet Vui Chong, Vladimir Bubanja, Hoang Van Vo
Summary: This study investigated the hydrogen adsorption on two-dimensional silicon carbide using molecular dynamics and density functional theory. The preferred hydrogen location was found to be on top of silicon atoms. The interaction energies and stability of different configurations were analyzed. The results provide guidance for the application of hydrogenated two-dimensional silicon carbide in optoelectronic manufacturing innovation.
Article
Chemistry, Physical
Mian Azmat, Abdul Majid, Mohammad Alkhedher, Sajjad Haider, Muhammad Saeed Akhtar
Summary: The prospect of using two-dimensional tetragonal samarium nitride (t-SmN) in photo-catalytic applications is being reported. First principles calculations were performed to study its structural, electronic, thermal, and photocatalytic properties. The material was found to be dynamically stable, thermally stable up to 1000 K, chemically inert at room temperature, and suitable for electrochemical reduction of water splitting. It also showed good light-harvesting ability from visible and ultraviolet regions of the solar spectrum.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Soumyadipta Pal, Subarna Datta
Summary: Using ab initio calculation, the structural, electronic and magnetic properties of Co2Nb1+xZ1-x (x = 0, 0.25, 0.50) were systematically investigated. It was found that except for Co2NbSn, all compositions did not exhibit martensitic structural transition, which was associated with Jahn-Teller distortion of Co 3d orbitals near the Fermi level. The density of states for Co2NbSn in both tetragonal and 4 O orthorhombic structures were examined. Co2NbSn showed metallic character, while Co2NbGa, Co2NbIn, and off-stoichiometric alloys were predicted to have partial half-metallic character. Nb doping increased the total magnetic moment due to increased Nb-Co hybridization of d orbitals.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Multidisciplinary Sciences
M. Tyunina, O. Pacherova, T. Kocourek, A. Dejneka
Summary: The study demonstrates that oxygen vacancies in ABO(3) perovskite oxides primarily result in strong anisotropic strain in epitaxial thin films, rather than weak isotropic expansion in bulk samples. This anisotropic chemical strain is explained by the preferential orientation of elastic dipoles of the vacancies, which have critical impacts on the synthesis and response functions of the films.
SCIENTIFIC REPORTS
(2021)
Article
Physics, Condensed Matter
Memoona Mehmood, Muhammad Nasir Rasul, Altaf Hussain, Muhammad Amir Rafiq, Faisal Iqbal, Alina Manzoor, Muhammad Azhar Khan
Summary: In this study, the physical properties of novel antiperovskite materials XCRh3 (X = Cd, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ce, Pr, Nd, Pm, Sm, Eu, Tb) were investigated using density functional theory. The study focused on structural, electronic, elastic, magnetic, and thermodynamic properties, and included the computation of mechanical parameters and analysis of thermodynamic properties under various pressures and temperatures.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Multidisciplinary Sciences
Artem. V. V. Tarasov, Tatiana. P. P. Makarova, Dmitry. A. A. Estyunin, Alexander. V. V. Eryzhenkov, Ilya. I. I. Klimovskikh, Vladimir. A. A. Golyashov, Konstantin. A. A. Kokh, Oleg. E. E. Tereshchenko, Alexander. M. M. Shikin
Summary: The antiferromagnetic ordering of MnBi2Te4, which remains invariant under the combination of time-reversal and primitive-lattice translation symmetries, endows it with topologically nontrivial nature and fundamental phenomena. Additionally, controlling the electronic and magnetic properties of this system can offer new ways for its application in devices. In this study, we theoretically modeled the changes in electronic structure resulting from the partial substitution of Mn with Sn in (Mn1-xSnx)Bi2Te4 compound using both Korringa-Kohn-Rostoker (KKR) Green's function method and the supercell approach with impurity in DFT methods. The calculated band structures were also compared with experimental measurements. We propose that the complex hybridization of Te-p(z) and Bi-p(z) orbitals with Sn and Mn orbitals leads to a nonlinear dependence of the band gap on the Sn content in Mn positions, potentially indicating topological phase transitions in the system.
Article
Chemistry, Multidisciplinary
Wei Wang, Senjun Yao, Shengwei Deng, Yinbin Wang, Chenglong Qiu, Chengli Mao, Jian-guo Wang
Summary: The study investigates the sintering behavior and mechanisms of supported Pt nanoparticles under different conditions using a combination of density functional theory calculations, machine learning, and molecular dynamics simulations. The results indicate that small-sized nanoparticles with high surface energy govern the sintering rate, and an increase in temperature promotes particle agglomeration.
Article
Materials Science, Multidisciplinary
Andrew C. Burgess, Edward Linscott, David D. O'Regan
Summary: A DFT+U-type corrective functional is proposed to enforce the flat plane condition on localized subspaces, eliminating the need for deriving from the Hubbard model. The functional shows low relative errors in total energy for dissociated s-block dimers and the challenging dissociated H+5 ring system. In comparison, bare PBE and PBE+U yield much higher energetic errors.
Article
Chemistry, Multidisciplinary
Mehrdad Rostami Osanloo, Kolade A. Oyekan, William G. Vandenberghe
Summary: Using first-principles calculations, the electronic, thermodynamic, and dielectric properties of 2D layered alkaline-earth hydroxides Ca(OH)(2) and Mg(OH)(2) were explored. It was found that bilayer Mg(OH)(2) with lower solubility in water showed higher out-of-plane dielectric constants and lower leakage currents than bilayer Ca(OH)(2).
Article
Physics, Applied
Sokrates T. Pantelides, D. Greg Walker, Mahmud Reaz, Massimo V. Fischetti, Ronald D. Schrimpf
Summary: This study reexamines the foundations of Shockley's equation and provides a robust theoretical justification for its kinetic-energy component and phonon component. The research findings show that Shockley's equation's exceptional applicability remains unchanged with a single-parameter fit.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Kolade Augustine Oyekan, Maarten Van de Put, Sabyasachi Tiwari, Carole Rossi, Alain Esteve, William Vandenberghe
Summary: This study investigates the role of subsurface oxygen vacancies in water splitting on titanium dioxide, finding that vacancy migration is essential for an exothermic pathway and only occurs in the presence of under-coordinated surface oxygen atoms. As water decomposition and surface oxygen saturation increase, migration of the subsurface V-O is inhibited.
APPLIED SURFACE SCIENCE
(2022)
Article
Physics, Applied
Emeric Deylgat, Sabyasachi Tiwari, William G. Vandenberghe, Bart Soree
Summary: Topological insulators have unique properties that make them promising for next-generation electronic devices. Passivating stanene nanoribbons is necessary for their implementation in devices. We develop a tight-binding model based on the Kane-Mele model and show its agreement with density functional theory calculations, capturing the physics of passivated edge bands.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Aaron Kramer, Ruth Pachter, Julia W. P. Hsu, William G. G. Vandenberghe
Summary: Although cyclic voltammetry (CV) measurements in solution have been widely used to determine the highest occupied molecular orbital energy (E-HOMO) of semiconducting organic molecules, the discrepancies observed in different solvents have not been well understood. In this study, we investigate the solvent effects on E-HOMO using density functional theory and molecular dynamics calculations. We find that the first solvation shell method can accurately capture the E-HOMO variation, while the implicit method cannot. Our findings suggest that the solvent choice should be taken into account when reporting, interpreting, or comparing E-HOMO values obtained by CV measurements.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Engineering, Electrical & Electronic
Emeric Deylgat, Edward Chen, Massimo Fischetti, Bart Soree, William G. Vandenberghe
Summary: This study compares the contact resistance and image-force barrier lowering (IFBL) for four different metal-dielectric-two-dimensional (2D) material configurations. The analysis considers different geometries of edge contacts and calculates the contact resistivity using the WKB approximation. The optimal configuration achieves a 50-fold reduction in contact resistance compared to the situation without considering IFBL.
SOLID-STATE ELECTRONICS
(2022)
Article
Chemistry, Physical
Aaron Kramer, Waldemar Kaiser, Boya Zhang, Lakshmi N. S. Murthy, Alessio Gagliardi, Julia W. P. Hsu, William G. Vandenberghe
Summary: Organic solar cells using small molecule donors have lower fill factors compared to those using polymer donors. This is due to the limited collection region of charges in small molecule solar cells, while polymer solar cells can collect charges from a deeper volume. The fill factor of small molecule solar cells can be improved by adjusting the active layer morphology or reducing the energy offset between the donor and acceptor.
Article
Physics, Applied
Sabyasachi Tiwari, Maarten L. Van de Put, Kristiaan Temst, William G. Vandenberghe, Bart Soree
Summary: To design fast memory devices, the combination of a two-dimensional (2D) magnet and a 2D topological insulator (TI) is proposed as a viable option. The spin-charge dynamics between 2D magnets and 2D TIs are theoretically modeled using the adiabatic approximation. It is shown that magnetic domains of a ferromagnet can be switched using the spin torque from spin-polarized edge states of a 2D TI, and the switching is strongly dependent on the interface exchange.
PHYSICAL REVIEW APPLIED
(2023)
Article
Nanoscience & Nanotechnology
Madhuchhanda Brahma, Maarten L. L. Van de Put, Edward Chen, Massimo V. V. Fischetti, William G. G. Vandenberghe
Summary: In this study, the impact of surrounding dielectrics and image-force barrier-lowering on the resistance of Schottky edge-contacts in metal-2D-material transistors is investigated. The electrostatic potential is calculated numerically using the Poisson equation, while the transmission probability is computed using the Wentzel-Kramers-Brillouin approximation. The results show that low-kappa surrounding dielectrics are crucial for achieving low resistance monolayer-TMD edge-contacts.
NPJ 2D MATERIALS AND APPLICATIONS
(2023)
Article
Engineering, Electrical & Electronic
William G. Vandenberghe, Mehrdad Rostami Osanloo
Summary: Recent developments in the field of two-dimensional (2D) van der Waals (vdW) dielectrics have attracted great interest for their potential applications in future CMOS technologies. This article highlights our recent progress in discovering 2D vdW dielectrics, which is crucial for the development of vdW transistor technology. We provide an overview of how to calculate the dielectric properties of 2D vdW dielectric candidates using density functional theory, and demonstrate how to quantify the expected leakage current through such dielectrics by using various materials.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Physics, Applied
Sarah R. Evans, Emeric Deylgat, Edward Chen, William G. Vandenberghe
Summary: The team introduced an alternative technique to determine the potential energy of image-force barrier lowering (IFBL) in the contact between two-dimensional semiconductors and metals, and identified tunable parameters for reducing Schottky barriers and contact resistance.
PHYSICAL REVIEW APPLIED
(2023)
Article
Computer Science, Information Systems
Ping-Ju Chuang, Ali Saadat, Maarten L. L. van de Put, Hal Edwards, William G. G. Vandenberghe
Summary: We propose an innovative method that combines optimization algorithms and technology computer-aided design to automatically optimize LDMOS devices with a field-oxide structure. The figure-of-merit (FOM), defined as the square of the breakdown voltage divided by the specific on-resistance, serves as the objective function for our optimization. We compare the performance of three algorithms - Nelder-Mead, Powell, and Bayesian Optimization - and find that Bayesian Optimization is the most data-efficient method to find the global optimized structure in the multi-domain design space.
Article
Chemistry, Inorganic & Nuclear
Maria Isabel Mendoza Diaz, Andrea Balocchi, Kolade Oyekan, Kui Tan, William G. Vandenberghe, Alain Esteve, Carole Rossi
Summary: TiO2 thin films with a combination of anatase and rutile phases were prepared by sputter deposition. The post-annealing step at 200 degrees C resulted in a 5-fold increase in H-2 production. In-depth analysis revealed the significant role of intermediate states, OH- and Ti3+ defects, as well as ethanol-induced hole traps in the photocatalytic performance of the TiO2 films.
DALTON TRANSACTIONS
(2022)
Article
Engineering, Electrical & Electronic
Ali Saadat, Maarten L. van de Put, Hal Edwards, William G. Vandenberghe
Summary: This paper investigates the performance of Laterally-Diffused Metal-Oxide-Semiconductor (LDMOS) transistors with Semi-circular Field OXide (S-FOX) for mid-voltage power applications. Analytical and numerical methods are used to derive the ideal behavior of the drift region and optimize the doping concentration. The findings are validated through numerical simulations.
IEEE JOURNAL OF THE ELECTRON DEVICES SOCIETY
(2022)