Article
Materials Science, Multidisciplinary
Hyun-Joong Kim, Seongsoo Yoon, Jae-Hyun Ha, Won-Chang Choi, Jung-Il Hong
Summary: The absence of net magnetization in antiferromagnets makes their magnetic anisotropy strong and robust against external magnetic fields, requiring a heating and cooling process to realign the spin structure. However, mechanical vibrations with relatively low frequencies can substitute the heating step and enable local control of the exchange bias effect in antiferromagnets. This technique allows for repeated post-readjustment of exchange bias effect in various directions, promoting wider integrations of exchange-biased systems in novel magnetic devices.
Article
Physics, Multidisciplinary
Linjie Liu, Weijin Chen, Yue Zheng
Summary: In this study, researchers discovered a flexomagnetic effect and Hall effect in synthetic antiferromagnetic systems, and proposed the connection between these effects and the topological structures in the system. These findings provide new insights for research in related fields.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Yue Hu, Shiming Yan, Deyou Jin, Wen Qiao, Ru Bai, Tiejun Zhou
Summary: The Ki of Fe/MgO, Fe/Pt/MgO, and Fe/Ir/MgO heterostructures with strains from -4.5% to 4.5% were calculated in this study. It was found that the Fe/Pt/MgO and Fe/Ir/MgO exhibited much larger Ki values (2.415 mJ m(-2) and -4.468 mJ m(-2)) compared to Fe/MgO (0.840 mJ m(-2)). Strain can significantly manipulate the magnetic anisotropy of these structures. The origin of these behaviors was analyzed through layer-resolved, orbital-resolved, and k-resolved Ki calculations.
Article
Materials Science, Multidisciplinary
Hyeon-Kyu Park, Sang-Koog Kim
Summary: The study theoretically explored the ultrafast propagations of spin waves in antiferromagnetic Bloch-type domain walls and found that the dispersive relation of these spin waves shows extremely high group velocity without any forbidden gap. The results offer guidance for the development of ultrafast information signal processing in nanoscale magnonic circuits composed of antiferromagnetic domain walls.
Article
Materials Science, Multidisciplinary
F. Mahrouche, K. Rezouali, Z. C. Wang, J. Fernandez-Rossier, A. Molina-Sanchez
Summary: The electronic properties of the heterobilayer of vanadium and iron oxychlorides were studied, with weak interlayer coupling preserving the magnetic order of each monolayer in the heterobilayer, combining antiferromagnetic and ferromagnetic orders. Interlayer exchange should lead to exchange bias and the emergence of hybrid collective modes.
Article
Physics, Applied
J. Li, P. van Nieuwkerk, M. A. Verschuuren, B. Koopmans, R. Lavrijsen
Summary: This article explores a fast and cost-effective fabrication method for the production and characterization of monodisperse magnetic nanoplatelets. The influence of size on magnetic properties is analyzed. The results show that substrate conformal imprint lithography allows for efficient large-scale platelet fabrication.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Manisha Srivastava, Munima B. Sahariah, Ananthakrishnan Srinivasan
Summary: In this study, single phase X type Fe2CoGa Heusler alloy nanoparticles were successfully synthesized, and their size-dependent structural and magnetic properties were investigated. The experimental results show that Fe2CoGa nanoparticles exhibit high magnetic moment and Curie temperature, and are in a single domain superparamagnetic regime.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Shiwei Hua, Yihui Yin, Hao Liang, Yuanzhang Zhang, Yabin Yan
Summary: In this study, a theoretical framework for describing the distortion of substitutional solid solutions (SSSs) is proposed and validated. The framework can be used to predict lattice constants, track atomic equilibrium positions, and estimate the resistance to distortion.
MATERIALS & DESIGN
(2022)
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
Quantum Science & Technology
Tanvi P. Gujarati, Mario Motta, Triet Nguyen Friedhoff, Julia E. Rice, Nam Nguyen, Panagiotis Kl. Barkoutsos, Richard J. Thompson, Tyler Smith, Marna Kagele, Mark Brei, Barbara A. Jones, Kristen Williams
Summary: Modeling electronic systems is an important application for quantum computers. In this work, the authors propose a workflow to model chemical reactions on surfaces using quantum computing algorithms. They develop and compare two local embedding methods to determine active spaces and introduce a technique for circuit simplification to reduce the quantum resources required.
NPJ QUANTUM INFORMATION
(2023)
Article
Chemistry, Applied
Soumalya Roy, Pooja Shukla, Raman Kumar, Subash Chandra Sahoo, Tapan K. Pal, Amit Rajput, Julia Klak, Masahiko Hada, Kuduva R. Vignesh, Sourav Das
Summary: A series of dimetallic Zn-II-Ln(III) compounds were successfully prepared, and the single crystal XRD analysis revealed the connection between metallic ions through the phenolic oxygen atom of ligands. Magnetic studies showed the existence of antiferromagnetic interaction between Zn-II and Ln(III) metal centers.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Article
Physics, Applied
John Nance, Kawsher A. Roxy, Sanjukta Bhanja, Greg P. Carman
Summary: This study investigates a multiferroic antiferromagnet as a high-speed artificial synapse in artificial intelligence applications using a finite-element model coupling micromagnetics and dynamic strain. It successfully programs two intermediate states using strain pulses and finds the minimum programming time to be around 0.3 ns.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Rui Wu, Di Zhang, Tuhin Maity, Ping Lu, Jie Yang, Xingyao Gao, Shishun Zhao, Xiucheng Wei, Hao Zeng, Ahmed Kursumovic, Guang Tian, Weiwei Li, Chao Yun, Yongqiang Wang, Zengyao Ren, Ziyao Zhou, Ming Liu, Kelvin H. L. Zhang, Quanxi Jia, Jinbo Yang, Haiyan Wang, Judith L. MacManus-Driscoll
Summary: Adding antiferromagnet to a 3-1-type multiferroic nanocomposite can result in a large, self-biased magnetoelectric effect at room temperature.
NATURE ELECTRONICS
(2021)
Review
Physics, Condensed Matter
Yu Shiratsuchi, Kentaro Toyoki, Ryoichi Nakatani
Summary: The magnetoelectric (ME) effect involves a cross-coupling between unconjugated physical quantities, such as magnetization and electric field, often appearing in specific antiferromagnetic (AFM) insulators. There is a growing interest in using the ME effect for spintronic devices, where it serves as an input method for digital information. Research focuses on issues such as controlling the AFM domain state and understanding the switching mechanism and dynamics.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
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
Nanoscience & Nanotechnology
Mengen Wang, Sai Mu, Chris G. Van de Walle
Summary: The research found that the diffusion of Al on the surface of Ga2O3 is restricted compared to Ga, with migration barriers indicating more limited Al diffusion. Despite thermodynamically preferable octahedral sites, kinetic limitations often lead to Al also occupying tetrahedral sites in (AlxGa1-x)2O3.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
Jared M. Johnson, Hsien-Lien Huang, Mengen Wang, Sai Mu, Joel B. Varley, A. F. M. Anhar Uddin Bhuiyan, Zixuan Feng, Nidhin Kurian Kalarickal, Siddharth Rajan, Hongping Zhao, Chris G. Van de Walle, Jinwoo Hwang
Summary: The study focuses on the aluminum atom incorporation, defect formation, and phase stability in beta-(AlxGa1-x)(2)O-3 films for ultra-wide bandgap applications, utilizing a combination of STEM and DFT to explain atomic scale structural characteristics and properties. The research finds that aluminum occupies octahedral and tetrahedral sites due to surface reconstructions and kinetic limitations, ultimately limiting the stability of the beta-phase. Local heterogeneity of composition leads to the formation of planar defects, impacting the stability of the beta-phase and resembling the metastable gamma-phase.
Article
Chemistry, Physical
Chao-Fan Li, Kangning Zhao, Xiaobin Liao, Zhi-Yi Hu, Lei Zhang, Yan Zhao, Sai Mu, Yanxi Li, Yu Li, Gustaaf Van Tendeloo, Congli Sun
Summary: This study reveals the origin of heterogeneous oxygen release in layered cathodes and provides insights for the rational design of cathode materials with enhanced oxygen stability by suppressing cation migration.
ENERGY STORAGE MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Hyun Seok Oh, Khorgolkhuu Odbadrakh, Yuji Ikeda, Sai Mu, Fritz Koermann, Cheng-Jun Sun, Heh Sang Ahn, Kook Noh Yoon, Duancheng Ma, Cemal Cem Tasan, Takeshi Egami, Eun Soo Park
Summary: The study on element-resolved local lattice distortion in 3d transition-metal element CCAs reveals that ELLD is primarily dependent upon charge transfer among elements and affects properties through atomic-level pressure and orbital transition, providing a qualitative measure of effective atomic size to explain element-specific and macroscopic properties.
Article
Physics, Applied
Haochen Wang, Nicholas Adamski, Sai Mu, Chris G. van de Walle
Summary: This study provides a detailed analysis of the spontaneous and piezoelectric polarization behaviors of aluminum nitride alloy with Sc addition. It is found that the virtual crystal approximation produces accurate results for polarization but falls short in describing the phase stability of the alloy. Additionally, the internal-strain contribution dominantly enhances the piezoelectric properties induced by Sc, with the value of u increasing with scandium concentration, bringing the alloy closer to a layered hexagonal structure locally.
JOURNAL OF APPLIED PHYSICS
(2021)
Correction
Materials Science, Multidisciplinary
K. D. Belashchenko, Alexey A. Kovalev, M. van Schilfgaarde
PHYSICAL REVIEW MATERIALS
(2021)
Article
Physics, Applied
Joseph Casamento, Hyunjea Lee, Takuya Maeda, Ved Gund, Kazuki Nomoto, Len van Deurzen, Wesley Turner, Patrick Fay, Sai Mu, Chris G. van de Walle, Amit Lal, Huili (Grace) Xing, Debdeep Jena
Summary: Epitaxial ScxAl1-xN thin films grown on metal polar GaN substrates exhibit high relative dielectric permittivity, the largest among existing nitride materials. The films also have polarization discontinuity, which can be utilized for extending transistor operation in power electronics and high-speed microwave applications.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Sai Mu, Chris G. Van de Walle
Summary: This study uses density functional theory to assess the phase stability of monoclinic Ga2O3 and (AlxGa1-x)(2)O-3 alloys. It finds that the gamma and kappa phases of (AlxGa1-x)(2)O-3 have the lowest enthalpy of formation at 62.5% and 50% Al concentrations, respectively. At finite temperature, lattice vibrations tend to stabilize the kappa phase and destabilize the alpha and gamma phases, with the configurational entropy of the gamma phase playing a substantial role in stabilizing it.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Xun Li, Seung-Hwan Do, Jiaqiang Yan, Michael A. McGuire, Garrett E. Granroth, Sai Mu, Tom Berlijn, Valentino R. Cooper, Andrew D. Christianson, Lucas Lindsay
Summary: Phonon-derived behaviors play an important role in indicating novel phenomena in transition metal trihalides. This study explores the vibrational properties of the ferromagnetic honeycomb lattice material CrCl3 and introduces an efficient dynamic method for understanding phonon behaviors in various materials. The findings provide insights into spin-lattice couplings and open new avenues for studying phonons in layered magnets.
Proceedings Paper
Engineering, Electrical & Electronic
Mengen Wang, Sai Mu, Chris G. Van de Walle
Summary: This paper discusses the diffusion behavior of dopants and point defects in monoclinic gallium oxide, as well as the diffusion of hydrogen in gallium oxide. The results provide important guidance for controlling doping in gallium oxide and its alloys.
OXIDE-BASED MATERIALS AND DEVICES XIII
(2022)
Article
Materials Science, Multidisciplinary
Sai Mu, Mengen Wang, Joel B. Varley, John L. Lyons, Darshana Wickramaratne, Chris G. Van de Walle
Summary: We used hybrid density functional calculations to analyze n-type doping in monoclinic (AlxGa1-x)(2)O-3 alloys. Our study focused on the impact of silicon, carbon, and hydrogen as impurities in metal-organic chemical vapor deposition (MOCVD) and their effect on the structural properties and charge-state transition levels of the alloys.
Article
Physics, Multidisciplinary
Sai Mu, Kiranmayi D. Dixit, Xiaoping Wang, Douglas L. Abernathy, Huibo Cao, Stephen E. Nagler, Jiaqiang Yan, Paula Lampen-Kelley, David Mandrus, Carlos A. Polanco, Liangbo Liang, Gabor B. Halasz, Yongqiang Cheng, Arnab Banerjee, Tom Berlijn
Summary: This study investigates the phonon structure of alpha-RuCl3 and finds that certain phonons in the material have significantly reduced velocities, potentially dominating the observability of the half-integer plateaus in the thermal Hall conductance. The findings are crucial for understanding the controversy surrounding the observation of this phenomenon.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Wuzhang Fang, K. D. Belashchenko
Summary: Spin-orbit torques in a Mn2Au/heavy-metal bilayer, such as W or Pt, were calculated using the nonequilibrium Green's function technique. It was found that interfaces with W or Pt generate parallel dampinglike torques of opposite signs and antiparallel fieldlike and dampinglike torques that can penetrate deep into Mn2Au. The efficiency of the dampinglike torque depends strongly on the termination of the interface and the presence of spin-orbit coupling in Mn2Au.
Article
Materials Science, Multidisciplinary
G. G. Baez Flores, K. D. Belashchenko
Summary: In this study, the influence of interfacial intermixing on spin-orbit torque in Co/Pt bilayers was investigated using the first-principles nonequilibrium Green's function technique. The results showed that intermixing moderately enhanced the dampinglike torque, while strongly enhancing the previously small fieldlike torque to a level comparable to the dampinglike torque. The enhancement of the fieldlike torque was attributed to the interface between Co and the intermixed region.
Article
Materials Science, Multidisciplinary
Sai Mu, Andrew J. E. Rowberg, Joshua Leveillee, Feliciano Giustino, Chris G. Van de Walle
Summary: In this study, we investigated the conduction-band structure and electron mobility in rocksalt ScN using density functional theory. Our findings reveal a significant enhancement of electron mobility at high carrier concentrations. We also show how strain engineering can increase electron mobility, with different effects on (111) and (100) oriented ScN films.