Article
Physics, Multidisciplinary
Lukas Stuelke, Parashu Kharel, Paul M. Shand, Pavel Lukashev
Summary: Among the important physical parameters in spin-based electronics, magnetocrystalline anisotropy and spin polarization are crucial. Consideration of reduced geometry effects in magnetic thin-film materials, especially in relation to perpendicular magnetic anisotropy, can provide valuable insights for practical applications in this field.
Article
Chemistry, Physical
Jonathon N. Baker, Utpal N. Roy
Summary: This article re-examines the native defect chemistry of ZnTe and explores how it changes upon addition of selenium using state-of-the-art computational tools.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Physics, Applied
Y. Kitaoka, H. Imamura
Summary: The study focused on the first- and second-order magnetic anisotropy coefficients, K-1 and K-2, of Fe atomic monolayers on a MgO(001) substrate under an electric field. Results show that the electric field derivatives of K-1 and K-2 have opposite signs to each other in all systems studied.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Lupeng Chang, Hecheng Han, Huiling Zheng, Qiushi Wang, Yu Yan
Summary: This study investigates the effect of strain on the stability and large perpendicular magnetic anisotropy (PMA) in an atomically thin layer of Ir-doped WSe2 using first-principles calculations. The results show that a W-rich condition is energetically favorable for the Ir-doped WSe2 system compared to a Se-rich condition. It is found that the PMA can be enhanced by compressive strain, with the PMA under -2% compressive strain being almost double that of the strain-free system. The study elucidates the underlying mechanism of the compressive strain effect, providing a potential route to effectively tune the PMA of the Ir-doped WSe2 system.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Physics, Applied
Yukie Kitaoka, Hiroshi Imamura
Summary: First-principles calculations were used to investigate the effect of inserting magnetic layers at the Fe/MgO interface. The insertion of an Ir layer increased the magnetocrystalline anisotropy energy, while the insertion of a Fe/Co/Ir layer resulted in a large perpendicular magnetic anisotropy.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Katherine Inzani, Nabaraj Pokhrel, Nima Leclerc, Zachary Clemens, Sriram P. Ramkumar, Sinead M. Griffin, Elizabeth A. Nowadnick
Summary: Atomic-scale control of spins by electric fields is highly desirable for future technological applications. Magnetically doped Aurivillius-phase oxides present one route to achieve this, with magnetic ions substituted into the ferroelectric structure at dilute concentrations, resulting in spin-charge coupling. However, there has been minimal exploration of the ferroelectric switching pathways in this materials class, limiting predictions of the influence of an electric field on magnetic spins in the structure.
Article
Chemistry, Physical
Shiquan Feng, Jiankang Liu, Jun Chen, Lei Su, Feng Guo, Cuiming Tang, Chaosheng Yuan, Xuerui Cheng
Summary: In this paper, van der Waals heterostructures composed of g-ZnO and Janus WSSe monlayers were designed, and their band alignments and band gaps were modulated by applying strains for potential applications in photoelectric devices and as catalysts for water splitting.
APPLIED SURFACE SCIENCE
(2022)
Article
Spectroscopy
Mingquan Ding, Huijun Liu, Hongtai Jiang, Mingde Huang, Xuexin Tan, Yanghai Li, Weiliang Wang, Shaolin Zhang, Haiming Huang
Summary: The vibrational, electronic and Raman properties of monolayer Ti2C under planar symmetrical strain excited by two commonly used laser lines are investigated. The results show that strained Ti2C exhibits notable red (blue) shift characteristic in its Raman peaks compared to unstrained Ti2C. The polarization angle also affects the Raman intensity in different configurations. This study provides insights for experimental characterization and understanding the effects of strain on Ti2C.
JOURNAL OF RAMAN SPECTROSCOPY
(2022)
Article
Chemistry, Physical
Ayash O. Alrashdi, H. Bushra Munir, Rana Ali Ahmad, Mohammed M. Fadhali, A. Afaq, Abu Bakar, Suhad Ali Osman Abdallah
Summary: In this study, structural, electronic, and magnetic properties of ZnFe2O4 were investigated using density functional theory. The effects of Hubbard parameter U and spin orbit coupling on these properties were also observed. The results showed that zinc ferrite has high magnetic moments, indicating its potential for spintronics device fabrication.
Article
Materials Science, Multidisciplinary
Jiasheng Ji, Hengyong Bu, Yonghua Duan, Mingjun Peng, Huarong Qi, Xiaoqi Wang, Li Shen
Summary: In this study, the structural, electrical, elastic, and thermal properties of TM5Si3N (TM = V, Nb, and Ta) Nowotny phase were investigated using first-principles calculations. The results indicate that TM5Si3N Nowotny phases are dynamically and thermodynamically stable. The TM5Si3N compound forms strong TM-Si and TM-N bonds due to the hybridization between TM-d state and Si-p and N-p states. The elastic modulus and thermal conductivity of TM5Si3N were found to be anisotropic with different magnitudes for different elements.
Article
Materials Science, Multidisciplinary
Biao Wang, Yurong He, Nikolay Rodionov, Jiaqi Zhu
Summary: This study compares and analyzes the effects of uniaxial and isotropic strains on the thermal conductivity of diamond using first-principles calculations and the phonon Boltzmann transport equation. The findings reveal that the bond length deformation index plays a significant role in the thermal conductivity of diamond under isotropic strain, while both the bond angle and bond length affect the thermal conductivity during uniaxial strain. This study provides essential insights into the strain-thermal conductivity relationships of diamond and other crystalline materials.
MATERIALS TODAY PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Jing Zhang, Pavel A. Korzhavyi, Junjing He
Summary: The study reveals the effects of Cr and W on the high-temperature properties of Ni-based alloys through calculations and modeling, shedding light on the temperature and concentration dependencies of elastic properties, as well as solid solution hardening.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Physics, Condensed Matter
Peiyan Gao, Yi Zhong, Lanqing Xu, Yongping Zheng, Zhigao Huang
Summary: This paper investigates the magnetic properties of graphdiyne (GDY) doped with 5d transition metal (TM) atoms through first-principles calculations. The TM atoms are stably embedded within the triangular cavities of GDY, resulting in significant magneto-crystal anisotropy energy. The introduction of TM atoms at the top can greatly alter the magneto-crystal anisotropy energy value of the system, leading to a flip in the easy magnetization axis. Moreover, the magneto-crystal anisotropy energy value of Ta@GDY can be modulated by strain. The research unveils GDY as a promising substrate for two-dimensional magnetic materials in future magnetic memory devices.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
Yukie Kitaoka, Hiroshi Imamura
Summary: Recent research has shown that the perpendicular magnetic anisotropy (PMA) of magnetoresistive random access memory (MRAM) can be significantly enhanced by inserting an ultrathin LiF layer at an Fe/MgO interface. First-principles calculations revealed that the PMA enhancement is mainly due to the suppression of Fe and O atom mixing at the interface. Additionally, in-plane Fe-F coupling contributes positively to the magnetocrystalline anisotropy energy (MAE), while Fe-O coupling has a negative contribution. These findings are valuable for the design of high-PMA materials.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Ming Cheng, Zhenhua Zhang, Xiaojuan Yuan, Yong Liu, Zhihong Lu, Rui Xiong, Jing Shi
Summary: This study investigated the interface structure and MAE properties of Co2FeAl/MgAl2O4 heterostructures with high PMA using first principles calculations. The results showed that the Co-O interface can induce a large PMA effect, but is a metastable structure, while the FeAl-O interface has a smaller PMA effect. Additionally, enhancing the PMA effect of the FeAl-O interface can be achieved by adjusting strain, electric field, and doping.
Article
Chemistry, Physical
Rafael Costa-Amaral, Yoshihiro Gohda
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Physics, Multidisciplinary
Tomonori Tanaka, Yoshihiro Gohda
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2020)
Review
Materials Science, Multidisciplinary
Yoshihiro Gohda
Summary: This article discusses the microstructure effect on the development of high-performance permanent magnets, focusing on the interface between the main phase and intergranular phase, as well as the finite-temperature magnetism. Insights into the surface termination of main-phase grains and magnetic decoupling in SmFe12-based magnets are provided, along with discussions on atomic arrangements and magnetic properties of intergranular phases in Nd-Fe-B magnets. Additional elements like Cu and Ga are shown to decrease the Curie temperature of the intergranular phase.
SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS
(2021)
Article
Chemistry, Physical
Tomonori Tanaka, Yoshihiro Gohda
NPJ COMPUTATIONAL MATERIALS
(2020)
Article
Chemistry, Physical
Kishu Sugawara, Insung Seo, Shiro Yamazaki, Kan Nakatsuji, Yoshihiro Gohda, Hiroyuki Hirayama
Summary: The crystallized wetting layer beneath the Ag(111) islands on the Si(111)7 x 7 substrate was found to contribute to the formation of quantum-well states (QWSs). Compared to Ag islands nucleated directly on the substrate, the presence of a wetting layer caused a shift of one monolayer in the E-w relation.
Article
Physics, Applied
Rafael Costa-Amaral, Yoshihiro Gohda
Summary: This study investigates the influence of GGA deficiencies, d-band occupancy, and itinerancy on the magnetoelectric effect in Fe3Si/M/BaTiO3 heterostructures. It shows that modifying the interface composition can enhance magnetoelectricity and that controlling d-state energy levels and replacing certain metals can increase the interface ME effect.
PHYSICAL REVIEW APPLIED
(2021)
Article
Materials Science, Multidisciplinary
Shumpei Fujii, Takamasa Usami, Yu Shiratsuchi, Adam M. Kerrigan, Amran Mahfudh Yatmeidhy, Shinya Yamada, Takeshi Kanashima, Ryoichi Nakatani, Vlado K. Lazarov, Tamio Oguchi, Yoshihiro Gohda, Kohei Hamaya
Summary: Research shows that electric-field control can be used to control the magnetization vectors of ferromagnetic electrodes in multiferroic heterostructures. By combining the ferromagnetic Heusler alloy Co2FeSi with the ferroelectric oxide Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT), nonvolatile and repeatable magnetization vector switchings can be achieved. This approach has the potential to reduce write power in spintronic memory architectures.
NPG ASIA MATERIALS
(2022)
Article
Physics, Applied
Shunsuke Tsuna, Rafael Costa-Amaral, Yoshihiro Gohda
Summary: In this study, the mechanism behind the electric-field modulation of the anisotropic magnetoresistance (AMR) ratio in Co2FeSi/BaTiO3 heterostructures is investigated using density functional theory with the Hubbard U correction. The results show that the interface bonding effects are the origin of the electric-field modulation of the AMR via a -c domain-wall motion.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Amran Mahfudh Yatmeidhy, Yoshihiro Gohda
Summary: We investigate the microscopic origin of strain-induced changes in the magnetocrystalline anisotropy energy of Co2FeSi, Co2MnSi, and Fe3Si Heusler alloys using first-principles electron theory. The anisotropy modulation in Co2FeSi and Co2MnSi is dominated by the quadrupole moment of Co minority-spin states under strain within the (001) plane, leading to giant magnetoelectric couplings in multiferroic heterointerfaces containing these compounds. On the other hand, the strain-induced anisotropy modulation in Fe3Si has mixed contributing factors including the anisotropy term of the orbital magnetic moment and the quadrupole term.
APPLIED PHYSICS EXPRESS
(2023)
Article
Physics, Applied
Soma Nishino, Yoshihiro Gohda
Summary: The stable crystal structures of SmFe12-based permanent magnets, which are expected to have crystalline grain-boundary subphases, are examined by first-principles thermodynamics. A free-energy landscape of ternary Sm-Cu-Fe is constructed, overcoming the dynamical instability problem, to identify stable crystal structures dependent on temperatures and compositions. Cu-rich B2 Sm-Cu is substantially stabilized by both phonons and configurational entropy, and Fe atoms in the Cu sublattice of B27 SmCu contribute to the phase stabilization. These findings expand the stable composition region of nonmagnetic SmCu-based intermetallics by revealing the existence of B2-B27 two-phase equilibria.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Shunsuke Tsuna, Yoshihiro Gohda
Summary: First-principles investigations reveal that the presence of B in neodymium-magnet compounds leads to acoustic phonon hardening. Substituting B with other light elements results in a decrease in phonon frequencies with increasing atomic number. However, imaginary phonons in Nd2Fe14F are attributed to electronic states and atomic configurations, rather than the heavier mass of F. Additionally, the study shows that magnetic disordering reduces the softening of phonons in paramagnetic Nd2Fe14B compared to ferromagnetic Nd2Fe14B, suggesting that phonon effects decrease the Curie temperature by stabilizing the paramagnetic state.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
Satoru Enomoto, Sonju Kou, Taichi Abe, Yoshihiro Gohda
Summary: Computational examination of the phase equilibria in the Sm-Fe-Cu ternary system reveals the possibility of liquid-phase sintering producing nonmagnetic grain-boundary subphases in SmFe12-based magnets. The B2 Sm-Cu-Fe is identified as a potential nonmagnetic subphase, with attractive Cu-Fe interaction observed within the B2 sublattice. The equilibrium between the liquid phase of Sm-Cu and SmFe12 is also verified. The findings provide insights into the electron theory and suggest a feasible approach for liquid-phase sintering of SmFe12-based magnets.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Takahiro Ogino, Insung Seo, Hiroo Tajiri, Masashi Nakatake, Sho-Ichi Takakura, Yudai Sato, Yukio Hasegawa, Yoshihiro Gohda, Kan Nakatsuji, Hiroyuki Hirayama
Summary: Both the root 7 x root 3-In-rect film and the two-monolayer-thick In film on Si substrates showed superconductivity, with a similar Fermi surface contour but slightly different shapes. The interaction between the substrate and the films was found to have a minimal effect on the superconductivity, as the transition temperature T-c remained the same.
Correction
Materials Science, Multidisciplinary
Yasutomi Tatetsu, Shinji Tsuneyuki, Yoshihiro Gohda
Article
Materials Science, Multidisciplinary
Insung Seo, Shunsuke Yokota, Yousuke Imai, Yoshihiro Gohda
COMPUTATIONAL MATERIALS SCIENCE
(2020)
