Article
Materials Science, Multidisciplinary
Arun Parthasarathy, Egecan Cogulu, Andrew D. Kent, Shaloo Rakheja
Summary: This study discusses the precession and stability of the Neel order of antiferromagnets subjected to spin torque, focusing on the requirements for in-plane and normal components of spin polarization. The precessional motion is described as a damped-driven pendulum with hysteresis, showing critical values and frequency dependencies on the spin current.
Article
Physics, Multidisciplinary
Guochu Deng, Gang Zhao, Shuang Zhu, Zhenjie Feng, Wei Ren, Shixun Cao, Andrew Studer, Garry J. McIntyre
Summary: The spin dynamics of Mn4Nb2O9 were studied using inelastic neutron scattering, and a dynamic model was proposed to explain the observed spin-wave excitation spectrum. The study showed that the spin dynamics of this compound are dominated by antiferromagnetic interactions on the two MnO6 octahedron networks, and a spin gap and magnetic critical scattering were observed.
NEW JOURNAL OF PHYSICS
(2022)
Article
Chemistry, Physical
Xiang-Lin Huang, Sz-Chian Liou, Tan-Ju Yang, Hsin-An Chen, Hsiao-Wen Chen, Hsiang-Lin Liu, Wei-Tin Chen, Guo-Jiun Shu
Summary: Photocatalysis is a potential solution to energy shortage and greenhouse effect. CuFeO2 (CFO) is a material with a Delafossite structure and has been studied extensively. In this study, we successfully grew high-quality CFO single crystals using the optical floating-zone technique. CFO has a narrow band gap, high charge carrier mobility, and electrochemical stability. The magnetic phase transition and magnetic entropy change of CFO were also investigated.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Hao-Lan Zhang, Yuan-Qi Zhai, Hiroyuki Nojiri, Christian Schroeder, Hung-Kai Hsu, Yi-Tsu Chan, Zhendong Fu, Yan-Zhen Zheng
Summary: This study presents a method for spin wave excitation using heterometallic rings and predicts spin wave excitations at different temperatures. The study finds that antiferromagnetic exchange, dipole-dipole interaction, and ring topology play important roles in spin wave excitations at low temperatures.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Multidisciplinary Sciences
Jieming Sheng, Le Wang, Andrea Candini, Wenrui Jiang, Lianglong Huang, Bin Xi, Jize Zhao, Han Ge, Nan Zhao, Ying Fu, Jun Ren, Jiong Yang, Ping Miao, Xin Tong, Dapeng Yu, Shanmin Wang, Qihang Liu, Maiko Kofu, Richard Mole, Giorgio Biasiol, Dehong Yu, Igor A. Zaliznyak, Jia-Wei Mei, Liusuo Wu
Summary: Here, we report the study on the magnetic properties of the spin-1/2 triangular-lattice antiferromagnet Na2BaCo(PO4)2, which exhibits a significantly reduced ordered moment in the incommensurate antiferromagnetic ground state and a two-dimensional spin dispersion in the high-field polarized state. The microscopic exchange parameters of the spin Hamiltonian have been determined, and quantum critical behaviors with Bose-Einstein condensation of magnons near the saturation field have been observed. These findings provide exciting opportunities for exploring exotic quantum phenomena.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Review
Physics, Condensed Matter
A. Podlesnyak, S. E. Nikitin, G. Ehlers
Summary: Recent studies on spin dynamics in rare-earth orthorhombic perovskite oxides were reviewed using single-crystal inelastic neutron scattering. The identity of the rare-earth ion strongly influences the ground state and low-energy excitations, leading to different magnetic field-temperature phase diagrams and quantum spin states. The observation of fractional spinon continuum and quantum criticality highlights the potential of Kramers rare-earth based magnets in realizing various aspects of quantum low-dimensional physics.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
Yuehua Su, Shengyan Wang, Chao Zhang
Summary: This paper proposes a technique called coincidence inelastic neutron scattering (cINS) to detect two-spin magnetic correlations of magnetic materials, which goes beyond the direct detection capability of traditional inelastic neutron scattering (INS).
Article
Materials Science, Multidisciplinary
V. K. Bhartiya, S. Hayashida, K. Yu Povarov, Z. Yan, Y. Qiu, S. Raymond, A. Zheludev
Summary: In this study, single crystal inelastic neutron scattering was used to investigate spin-wave excitations in the fully polarized state of the frustrated quantum ferroantiferromagnet BaCdVO(PO4)(2). By fitting all eight exchange constants simultaneously to data from over 150 scans, a definitive quantitative model of the material was established, which was found to be substantially different from previous assumptions based on powder experiments.
Article
Physics, Condensed Matter
Y. Li, D. Phelan, F. Ye, H. Zheng, E. Krivyakina, A. Samarakoon, P. G. Labarre, J. Neu, T. Siegrist, S. Rosenkranz, S. Syzranov, A. P. Ramirez
Summary: By studying Fe(2)TiO(5) diluted with non-magnetic Ga, it was found that the material exhibits strongly geometrically frustrated spin glass characteristics at different p values.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Physics, Condensed Matter
Tao Xie, Chang Liu, Ryoichi Kajimoto, Kazuhiko Ikeuchi, Shiliang Li, Huiqian Luo
Summary: In this study, time-of-flight inelastic neutron scattering (INS) was used to investigate the spin fluctuation spectrum in the 112-type iron-based superconductor Ca0.82La0.18Fe0.96Ni0.04As2 (CaLa-112). The results showed that in-plane dispersions and the bandwidth of spin excitations in CaLa-112 closely resemble those in 122 systems. While the total fluctuating moments were larger in CaLa-112, the dynamic correlation lengths were similar, suggesting a common magnetic origin for superconductivity in iron arsenides.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Multidisciplinary Sciences
Qiyang Sun, Bin Wei, Yaokun Su, Hillary Smith, Jiao Y. Y. Lin, Douglas L. Abernathy, Chen Li
Summary: The study investigates the impact of spin-phonon coupling on the phonon system through experiments and calculations. Anomalous scattering spectral intensity is identified in antiferromagnetic nickel (II) oxide, revealing strong spin-lattice correlations. Magnetic scattering signature is observed in acoustic phonons, and a modified scattering cross-section model is proposed.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Physics, Multidisciplinary
Shang Gao, Ganesh Pokharel, Andrew F. May, Joseph A. M. Paddison, Chris Pasco, Yaohua Liu, Keith M. Taddei, Stuart Calder, David G. Mandrus, Matthew B. Stone, Andrew D. Christianson
Summary: This study uses spectral graph theory to approximate spiral spin liquids on a bipartite lattice and broadens the range of candidate materials that may support spiral spin liquid phases. Neutron scattering experiments on two compounds demonstrate the feasibility of this new approach and reveal potential limitations in experimental realizations.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Shang Gao, Michael A. McGuire, Yaohua Liu, Douglas L. Abernathy, Clarina dela Cruz, Matthias Frontzek, Matthew B. Stone, Andrew D. Christianson
Summary: Using neutron scattering, a spiral spin liquid has been realized in the van der Waals honeycomb magnet FeCl3. A continuous ring of scattering is directly observed, indicating the emergence of an approximate U(1) symmetry in momentum space.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Xiao Yuan, Peter S. Riseborough
Summary: Spin-excitons are sharp branches of dispersive triplet excitations found within the gap of paramagnetic Kondo Insulators. The application of a high applied magnetic field can destabilize the non-magnetic Kondo Insulating state through different routes depending on the strength of quasi-particle interactions: a transition to a field-induced antiferromagnetic state for strong interactions, and the closure of the hybridization gap for weak interactions. This study examines the effects of an applied magnetic field on spin-excitons, showing that they split into three branches proportional to the applied field, with the lowest-energy branch disappearing at the transition to the antiferromagnetic phase.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Physics, Applied
O. Stockert, F. Steglich
Summary: Heavy-fermion superconductors, historically discovered unconventional superconductors, serve as model systems for high-Tc superconductors. This review discusses the existence of a spin resonance in the superconducting state and its implications in heavy-fermion superconductors.
PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS
(2023)
Review
Physics, Atomic, Molecular & Chemical
Shojiro Kimura, Noriki Terada, Masayuki Hagiwara, Masashige Matsumoto, Hidekazu Tanaka
Summary: Electric dipole active magnetic resonance and nonreciprocal directional dichroism in magnetoelectric multiferroic materials in terahertz and millimeter wave regions are phenomena induced by dynamical magnetoelectric coupling. These phenomena have potential applications in microscopic magnetic excitation studies and optical diode functionalities.
APPLIED MAGNETIC RESONANCE
(2021)
Article
Physics, Multidisciplinary
Takashi Kurumaji, Taro Nakajima, Artem Feoktystov, Earl Babcock, Zahir Salhi, Victor Ukleev, Taka-hisa Arima, Kazuhisa Kakurai, Yoshinori Tokura
Summary: The study investigates the spin rotational structure of magnetic skyrmions in tetragonal polar magnet VOSe2O5 using polarized small-angle neutron scattering (SANS). It reveals consistent evidence of cycloidal spin modulation in all incommensurate phases, including the triangular skyrmion-lattice phase, along the c axis. Additionally, a field-induced incommensurate phase (IC-2 state) was identified near the skyrmion phase, suggesting the possibility of an anisotropic double-q state as an alternative spin structure to the provisional square skyrmion-lattice state.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2021)
Article
Multidisciplinary Sciences
Noriki Terada, Hiroaki Mamiya
Summary: Magnetic refrigeration is a method of cooling using a magnetic field, with current research focusing on lowering target temperatures and improving cooling efficiency. The proposed technique using small magnetic field changes and holmium shows promise for efficient cooling, offering an alternative to conventional methods.
NATURE COMMUNICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Hiroaki Mamiya, Noriki Terada, Masashi Hase, Naohito Tsujii, Hideaki Kitazawa
Summary: The effects of Sc substitution on metamagnetic transitions for erbium were investigated in order to find optimal magnetocaloric materials for high-efficient magnetic refrigeration. It was observed that the Neel temperature decreased with increasing Sc substitution. The metamagnetic transitions from antiferromagnetic-like to ferromagnetic-like configurations were accompanied by relatively large magnetic entropy changes for all samples. These findings are important for further studies on magnetic refrigeration utilizing the features of metamagnetic transitions.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Instruments & Instrumentation
Tatsuro Oda, Hitoshi Endo, Hidetoshi Ohshita, Tomohiro Seya, Yoshiji Yasu, Taro Nakajima, Masahiro Hino, Yuji Kawabata
Summary: In this study, a phase correction method is proposed for TOF-MIEZE neutron spin echo spectroscopy. The correction involves adjusting the phase shifts of the MIEZE signal to accurately measure the signal contrast decay, corresponding to the intermediate scattering function. Additionally, the method demonstrates the relationship between frequency shift of the TOF-MIEZE signal and path-length deviation for quantifying phase shifts larger than 2 pi.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2021)
Article
Chemistry, Multidisciplinary
Nguyen Duy Khanh, Taro Nakajima, Satoru Hayami, Shang Gao, Yuichi Yamasaki, Hajime Sagayama, Hironori Nakao, Rina Takagi, Yukitoshi Motome, Yoshinori Tokura, Taka-hisa Arima, Shinichiro Seki
Summary: This study extensively investigated the magnetic structures in the centrosymmetric tetragonal magnet GdRu2Si2, identifying a rich variety of double-Q magnetic structures and successfully reproducing the observed complex magnetic phase diagram using a theoretical framework. These results are important for understanding the skyrmion formation mechanism in centrosymmetric rare-earth compounds and suggest that itinerant electrons can host various unique multiple-Q spin orders in a simple crystal lattice system.
Article
Materials Science, Multidisciplinary
Jiawei Lai, A. Bolyachkin, N. Terada, S. Dieb, Xin Tang, T. Ohkubo, H. Sepehri-Amin, K. Hono
Summary: Fe2P-type compounds exhibit a giant magnetocaloric effect and are studied for room temperature applications. In this study, rare-earth-free compounds with cryogenic magnetocaloric effect were optimized using data mining and machine learning, demonstrating promising magnetocaloric performance.
Article
Chemistry, Inorganic & Nuclear
Alexei A. Belik, Ran Liu, Lei Zhang, Noriki Terada, Masahiko Tanaka, Kazunari Yamaura
Summary: An A-site-ordered quadruple perovskite NdMn7O12 was synthesized at high pressure and high temperature, and its crystal structure and magnetic properties were investigated. The study revealed structural and magnetic phase transitions at different temperatures, as well as complex frequency-dependent features.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Rina Takagi, Naofumi Matsuyama, Victor Ukleev, Le Yu, Jonathan S. White, Sonia Francoual, Jose R. L. Mardegan, Satoru Hayami, Hiraku Saito, Koji Kaneko, Kazuki Ohishi, Yoshichika Onuki, Taka-hisa Arima, Yoshinori Tokura, Taro Nakajima, Shinichiro Seki
Summary: This study reports the discovery of square and rhombic lattices of nanometric skyrmions in the centrosymmetric compound EuAl4, expanding the range of potential materials hosting skyrmions.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Xin Tang, H. Sepehri-Amin, N. Terada, A. Martin-Cid, I Kurniawan, S. Kobayashi, Y. Kotani, H. Takeya, J. Lai, Y. Matsushita, T. Ohkubo, Y. Miura, T. Nakamura, K. Hono
Summary: The authors demonstrate a series of materials with a large and reversible magnetocaloric effect, suitable for the full temperature range required for hydrogen liquefaction. By eliminating the magneto-structural phase transition, the giant magnetocaloric effect becomes reversible.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
H. Takagi, R. Takagi, S. Minami, T. Nomoto, K. Ohishi, M. -t. Suzuki, Y. Yanagi, M. Hirayama, N. D. Khanh, K. Karube, H. Saito, D. Hashizume, R. Kiyanagi, Y. Tokura, R. Arita, T. Nakajima, S. Seki
Summary: The spontaneous topological Hall effect in triangular lattice compounds CoTa3S6 and CoNb3S6 is experimentally demonstrated, combining non-coplanar antiferromagnetic order with finite scalar spin chirality in the absence of a magnetic field. These compounds exhibit unconventionally large spontaneous Hall effects despite their small net magnetization, and the mechanism behind this phenomena is explained by the topological Hall effect associated with scalar spin chirality. The results suggest that the scalar spin chirality mechanism offers a promising route for the realization of a giant spontaneous Hall response in compensated antiferromagnets.
Article
Materials Science, Multidisciplinary
Noriki Terada, Hiroaki Mamiya, Hiraku Saito, Taro Nakajima, Takafumi D. Yamamoto, Kensei Terashima, Hiroyuki Takeya, Osamu Sakai, Shinichi Itoh, Yoshihiko Takano, Masashi Hase, Hideaki Kitazawa
Summary: Magnetic refrigeration materials containing rare-earth ions have potential for hydrogen liquefaction and energy storage applications. The effect of crystal-field level splitting on magnetic entropy change is systematically investigated in HoB2, comparing mean-field calculations with neutron scattering experiments. This study is important for developing compounds with high magnetic entropy change and advancing the design of magnetic refrigeration materials.
COMMUNICATIONS MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Jiwon Ju, Hiraku Saito, Takashi Kurumaji, Max Hirschberger, Akiko Kikkawa, Yasujiro Taguchi, Taka-hisa Arima, Yoshinori Tokura, Taro Nakajima
Summary: We investigated the magnetic structures of Gd2PdSi3, a centrosymmetric skyrmion material, using polarized neutron scattering. Our results confirmed the elliptic screw-type magnetic modulation in zero field with a propagation vector of (q, 0, 0). As the temperature increases, the system undergoes a magnetic phase transition while maintaining the incommensurate q-vector of (q, 0, 0). In the ground state, the system contains equal fractions of left-handed and right-handed screw-type orders, as expected from the centrosymmetric crystal structure.
Article
Materials Science, Multidisciplinary
Noriki Terada, Tomohito Nakano, Claire Colin, Anne Stunault, Navid Qureshi, Bachir Ouladdiaf, Hirohiko Sato
Summary: The ferroelectricity and magnetic ordering of multiferroic orthorhombic perovskite YMnO3 were studied, revealing the ferroelectric polarization, magnetic structure, and collinear E-type ordering in the low-temperature ferroelectric phase. Experimental results indicated a single collinear E-type structure with small incommensurability as the magnetic ground state of YMnO3.
Article
Materials Science, Multidisciplinary
Max Hirschberger, Yoshio Kaneko, Leonie Spitz, Taro Nakajima, Yasujiro Taguchi, Yoshinori Tokura
Summary: In metallic pyrochlore Nd2Mo2O7, the stability of the canted ferromagnetic state and the tilting angle of molybdenum spins in (Nd1-xCax)(2)Mo2O7 (x <= 0.15) were demonstrated through magnetic susceptibility measurements. The change in Mo-Mo and Mo-Nd magnetic couplings above x = 0.22 results in the canted ferromagnetic state transitioning to a spin-glass metallic region. Contributions to the Curie-Weiss law from two magnetic species were systematically separated.