Article
Multidisciplinary Sciences
Shaomian Qi, Di Chen, Kangyao Chen, Jianqiao Liu, Guangyi Chen, Bingcheng Luo, Hang Cui, Linhao Jia, Jiankun Li, Miaoling Huang, Yuanjun Song, Shiyi Han, Lianming Tong, Peng Yu, Yi Liu, Hongyu Wu, Shiwei Wu, Jiang Xiao, Ryuichi Shindou, X. C. Xie, Jian-Hao Chen
Summary: Researchers discovered that giant electrically tunable anisotropy in the transport of second harmonic thermal magnons can be achieved in the van der Waals antiferromagnetic insulator CrPS4 with modest gate current. Taking advantage of this large and tunable anisotropy, they demonstrated multi-bit read-only memories based on the anisotropy of magnon transport in CrPS4.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Applied
Bing Zhao, Bogdan Karpiak, Anamul Md Hoque, Pallavi Dhagat, Saroj P. Dash
Summary: This study investigates heterostructure devices of Fe3GeTe2 (FGT) two-dimensional magnets with monolayer graphene. The FGT Hall-bar devices show robust ferromagnetism and strong perpendicular anisotropy at low temperatures. The electrical transport properties of FGT/graphene heterostructure devices exhibit weak temperature dependence in tunneling transport. These findings have significance for engineering spintronic devices based on vdW heterostructures.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
A. Koriki, M. Misek, J. Pospisil, M. Kratochvilova, K. Carva, J. Prokleska, P. Dolezal, J. Kastil, S. Son, J-G Park, V Sechovsky
Summary: A comprehensive study of the magnetocrystalline anisotropy of a layered van der Waals ferromagnet VI3 was conducted, revealing changes in angular signals in different magnetic regions and structural phases.
Review
Chemistry, Multidisciplinary
Kun Zhao, Dawei He, Shaohua Fu, Zhiying Bai, Qing Miao, Mohan Huang, Yongsheng Wang, Xiaoxian Zhang
Summary: In recent years, research on van der Waals heterostructures has gained significant attention, where stacking various 2D materials together leads to the formation of new properties. Various interfacial modulation methods have been applied to regulate the interfacial coupling of such heterostructures.
Article
Chemistry, Multidisciplinary
Sung Jong Kim, Dongwon Choi, Kyoung-Whan Kim, Ki-Young Lee, Duck-Ho Kim, Seokmin Hong, Joonki Suh, Changgu Lee, Se Kwon Kim, Tae-Eon Park, Hyun Cheol Koo
Summary: This study characterizes the magnetic anisotropy of Fe3GeTe2 layers using magnetometric techniques and confirms its intrinsic nature influenced by both interfacial and bulk properties. Additionally, it demonstrates that the interfacial anisotropy in Fe3GeTe2-based heterostructures can be locally controlled by adjacent layers, leading to multiple magnetic behaviors in a single channel.
Article
Engineering, Electrical & Electronic
Ming Tang, Junwei Huang, Feng Qin, Kun Zhai, Toshiya Ideue, Zeya Li, Fanhao Meng, Anmin Nie, Linglu Wu, Xiangyu Bi, Caorong Zhang, Ling Zhou, Peng Chen, Caiyu Qiu, Peizhe Tang, Haijun Zhang, Xiangang Wan, Lin Wang, Zhongyuan Liu, Yongjun Tian, Yoshihiro Iwasa, Hongtao Yuan
Summary: Controlling the magnetic anisotropy of ferromagnetic materials is crucial for the development of magnetic switching devices and spintronic applications. This study demonstrates the gate-tunable modulation of magnetic anisotropy in the van der Waals ferromagnet Fe5GeTe2, allowing for continuous rotation of the magnetic easy axis from an out-of-plane to an in-plane orientation. The results show that the modulation of anisotropy can be achieved via a spin-flop pathway and the range of modulation is significant, from 2.11 to -0.38 MJ m(-3). Additionally, temperature can also be used to tune the anisotropy.
NATURE ELECTRONICS
(2023)
Article
Chemistry, Multidisciplinary
Shuai Fu, Xiaoyu Jia, Aliaa S. Hassan, Heng Zhang, Wenhao Zheng, Lei Gao, Lucia Di Virgilio, Sven Krasel, David Beljonne, Klaas-Jan Tielrooij, Mischa Bonn, Hai I. Wang
Summary: By electrically tuning the defect occupancy, we achieved full control over charge separation states and photogating field direction at the graphene-WS2 vdW interface. Our results showed that the electron occupancy of two in-gap states, presumably originating from sulfur vacancies, explained the observed rich interfacial charge transfer dynamics and electrically tunable photogating fields, providing microscopic insights for optimizing optoelectronic devices.
Article
Chemistry, Multidisciplinary
Xi Zhang, Le Wang, Huimin Su, Xiuquan Xia, Cai Liu, Bingbing Lyu, Junhao Lin, Mingyuan Huang, Yingchun Cheng, Jia-Wei Mei, Jun-Feng Dai
Summary: The strain tunability of perpendicular magnetic anisotropy in van der Waals ferromagnet VI3 was studied. The experiment showed that the coercivity of VI3 flakes can be enhanced by applying external strain. Furthermore, calculations revealed that the increased magnetic anisotropy energy under strain contributes to the enhancement of coercivity. In contrast, the strain tunability of coercivity in CrI3 flakes is limited.
Article
Chemistry, Multidisciplinary
Amanda L. Coughlin, Dongyue Xie, Xun Zhan, Yue Yao, Liangzi Deng, Heshan Hewa-Walpitage, Trevor Bontke, Ching-Wu Chu, Yan Li, Jian Wang, Herbert A. Fertig, Shixiong Zhang
Summary: The study examines the self-intercalated structures and vdW superstructures in Cr1+delta Te2 nanoplates, revealing magnetic behaviors distinct from bulk chromium tellurides. The spontaneous formation of twisted vdW superstructures offers insight into the diverse magnetic properties of intercalated vdW magnets and potential building blocks for vdW-based spintronics.
Article
Materials Science, Characterization & Testing
Jieting Geng, Yuka Yuan, Kai Liu, Jing Hua
Summary: High-damping rubber materials play a crucial role in achieving high-performance green tires by reducing noise and vibration, providing auto-braking, and increasing service life. However, the mismatched surface energy between non-polar and polar rubber materials hinders their interfacial interaction and compatibility. In this study, a multi-functionalization high vinyl polybutadiene rubber (MFHVBR)/ethylene-vinyl acetate rubber (EVM) blend was prepared through simple mechanical blending, enhancing the interfacial compatibility and van der Waals interaction. The optimized MFHVBR/EVM blends exhibited ultrahigh damping properties with a wide effective damping temperature range, covering the service temperature of tires, along with improved vulcanization efficiency and physical mechanical properties. This study provides a feasible pathway for developing low-cost and high-performance green tire tread rubber materials.
Article
Chemistry, Multidisciplinary
Andrey A. Vyshnevyy, Georgy A. Ermolaev, Dmitriy V. Grudinin, Kirill V. Voronin, Ivan Kharichkin, Arslan Mazitov, Ivan A. Kruglov, Dmitry I. Yakubovsky, Prabhash Mishra, Roman V. Kirtaev, Aleksey V. Arsenin, Kostya S. Novoselov, Luis Martin-Moreno, Valentyn S. Volkov
Summary: This study demonstrates that using anisotropic materials can improve the characteristics of nanophotonic devices by expanding the range of parameters at which single-mode propagation can be achieved.
Article
Chemistry, Multidisciplinary
Andrey A. Vyshnevyy, Georgy A. Ermolaev, Dmitriy V. Grudinin, Kirill V. Voronin, Ivan Kharichkin, Arslan Mazitov, Ivan A. Kruglov, Dmitry I. Yakubovsky, Prabhash Mishra, Roman V. Kirtaev, Aleksey V. Arsenin, Kostya S. Novoselov, Luis Martin-Moreno, Valentyn S. Volkov
Summary: There is a high demand for high-refractive-index and low-loss materials in on-chip nanophotonics. The use of van der Waals (vdW) materials with a high refractive index can provide an advanced alternative. However, it was not clear if the optical anisotropy perpendicular to the layers might hinder the development of vdW nanophotonics. By studying WS2-based waveguides, it was discovered that the low refractive index in the direction perpendicular to the atomic layers actually improves the characteristics of the devices.
Article
Chemistry, Multidisciplinary
Hideki Matsuoka, Stewart Edward Barnes, Jun'ichi Ieda, Sadamichi Maekawa, Mohammad Saeed Bahramy, Bruno Kenichi Saika, Yukiharu Takeda, Hiroki Wadati, Yue Wang, Satoshi Yoshida, Kyoko Ishizaka, Yoshihiro Iwasa, Masaki Nakano
Summary: This research presents strong out-of-plane magnetic anisotropy at the interface between two different vdW materials, and proposes a simple model to explain the observations. These results demonstrate a new magnetic proximity effect at the vdW interface, expanding the horizons of emergent phenomena achievable in vdW heterostructures.
Article
Chemistry, Multidisciplinary
Chenhui Zhang, Chen Liu, Senfu Zhang, Bojian Zhou, Chaoshuai Guan, Yinchang Ma, Hanin Algaidi, Dongxing Zheng, Yan Li, Xin He, Junwei Zhang, Peng Li, Zhipeng Hou, Gen Yin, Kai Liu, Yong Peng, Xi-Xiang Zhang
Summary: This article reports the observation of dipole skyrmions with unconventional helicity polarization in a van der Waals ferromagnet, Fe5-delta GeTe2. Experimental evidence demonstrates that short-range superstructures in Fe5-delta GeTe2 lead to helicity polarization, which is caused by a localized DMI contribution that breaks the degeneracy of opposite helicities.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Li Chen, Chuan Jiang, Maoyou Yang, Dongchao Wang, Changmin Shi, Hongmei Liu, Guangliang Cui, Xiaolong Li, Jiakuo Shi
Summary: The electronic properties and interfacial contact of the graphene/CrSiTe3 heterostructure can be modulated by adjusting the interfacial distance and applying an external electric field. Changing the distance leads to an increase in the band gap and a transition from n-type to p-type Schottky contact. Applying a positive electric field enhances the p-type Schottky contact and promotes interfacial charge transfer to graphene, while applying a negative electric field strengthens the n-type Schottky contact and reduces interfacial charge transfer to graphene. An Ohmic contact is achieved when a positive electric field of 0.41 eV angstrom(-1) is applied. This study provides an approach to manipulate interfacial properties, which is crucial for future experimental studies and graphene-based interfaces.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Applied
Shohei Tada, Duanxing Li, Mina Okazaki, Hiroka Kinoshita, Masahiko Nishijima, Noriko Yamauchi, Yoshio Kobayashi, Kenta Iyoki
Summary: Highly efficient CO2 utilization methodologies combining methanol synthesis catalysts and methanol conversion catalysts have been developed. The use of ZnO/ZrO2 as the catalyst for methanol synthesis and MOR zeolites as the catalyst for methanol conversion enables one-pass hydrocarbon production via CO2 hydrogenation. By physically mixing these catalysts, bifunctional catalysts are formed, which operate at low pressure and have shown promising results in terms of olefin selectivity.
Review
Physics, Applied
J. Robertson, H. Naganuma, H. Lu
Summary: Magnetic tunnel junctions with MgO/Fe interfaces and perpendicular spin directions are widely used in spin-transfer torque magnetic random-access memories. The future scaling of MTJs may affect materials choices, including comparing 2D h-BN materials with existing MgO tunnel barriers. The effects of different h-BN interfacial sites on Ni or Co are compared in terms of their magnetoresistance, magnetic isotropy, and the pillow effect, balanced against the favorable chemical thermodynamics of the existing MgO barriers and MgO/Fe interfaces.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Victor Zatko, Regina Galceran, Marta Galbiati, Julian Peiro, Florian Godel, Lisa-Marie Kern, David Perconte, Fatima Ibrahim, Ali Hallal, Mairbek Chshiev, Benjamin Martinez, Carlos Frontera, Lluis Balcells, Piran R. Kidambi, John Robertson, Stephan Hofmann, Sophie Collin, Frederic Petroff, Marie-Blandine Martin, Bruno Dlubak, Pierre Seneor
Summary: 2D materials can be manipulated by proximity effects to modify their electronic structure, allowing for the creation of unique properties in interfaces and heterostructures. In this study, we investigate the possibility of using a ferromagnetic insulator-graphene electrode to design a magnetic tunnel junction. Through the observation of tunnel magnetoresistance, we confirm the emergence of spin polarization in proximitized graphene layers, which is induced by a spin-dependent splitting of the Dirac band structure. This opens up opportunities for utilizing 2D quantum materials in spintronics applications, such as memory cells and logic circuits.
Article
Materials Science, Multidisciplinary
Tomohiro Ichinose, Hiroshi Naganuma
Summary: Evaluation of the bidirectional magnetoelectric effect in a BiFeO3/NiFeCuMo bilayer demonstrates that the electronically controlled ME effect and magnetically controlled ME effect have separate origins. The magnetically controlled ME effect is attributed to the cycloidal magnetic structure of the bulk BFO, while the electronically controlled ME effect is achieved through electric-field-induced ferroelectric polarization switching. The bidirectional ME effect is a result of the combination of the cycloidal magnetic structure throughout the film and an uncompensated weak ferromagnetic interface near the BFO/NiFeCuMo interface.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Physics, Applied
Sajid Husain, Nicholas Figueiredo-Prestes, Olivier Fayet, Sophie Collin, Florian Godel, Eric Jacquet, Nicolas Reyren, Henri Jaffres, Jean-Marie George
Summary: Ferrimagnetic insulators (FIMIs) are promising materials for spin-orbit torque (SOT) devices due to their ability to propagate a spin current without Ohmic losses. The origin of the anomalous Hall effect (AHE) in FIMI/heavy metal (HM) systems has remained unclear. In this study, we demonstrate that the AHE and spin Hall magnetoresistance (SMR) in FIMI/HM bilayer heterostructures have the same origin.
APPLIED PHYSICS LETTERS
(2023)
Review
Physics, Applied
Hiroshi Naganuma
Summary: The feasibility of scaling X nm-generation spintronic memory using magnetic tunnel junctions (MTJs) is investigated in order to keep up with the scaling of state-of-the-art transistors. Various solutions including magnetocrystalline anisotropy, shape magnetic anisotropy, and multi-interfacial magnetic anisotropy are proposed to overcome thermal fluctuation even at the X nm-generation. This study focuses on the high magnetocrystalline anisotropy of L1(0)-ordered alloy combined with graphene as a tunneling barrier in MTJs, and investigates their scaling potential for both 10-year data retention and nanosecond writing efficiency through micromagnetic simulation. By using a junction diameter of 7 nm, the MTJs achieve 10-year data retention and high-speed writing of 2.2 ns simultaneously.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
H. Naganuma, M. Uemoto, H. Adachi, H. Shinya, I. Mochizuki, M. Kobayashi, A. Hirata, B. Dlubak, T. Ono, P. Seneor, J. Robertson, K. Amemiya
Summary: A crystallographically heterogeneous moire interface is formed between hexagonal graphene (Gr) and tetragonal L1(0)-FePd alloy via van der Waals forces. Robust interfacial perpendicular magnetic anisotropy is observed on the L1(0)-FePd side of the Gr/L1(0)-FePd heterogeneous interface. This study focuses on the Gr side of the interface.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Applied
Kakeru Fujiwara, Taiki Akutsu, Masahiko Nishijima, Shohei Tada
Summary: In this study, ZnO-ZrO2 solid solution with high specific surface area was synthesized by flame spray pyrolysis under a lean-fuel condition. The dispersion state of Zn species in the particles and the presence of the Zrd(delta+) state were investigated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy. The catalytic activity of 28 at% ZnO-ZrO2 for CO2-to-methanol hydrogenation was found to be higher than that of 40 at% ZnO-ZrO2.
TOPICS IN CATALYSIS
(2023)
Article
Physics, Applied
Pauline Dufour, Thomas Maroutian, Maxime Vallet, Kinnary Patel, Andre Chanthbouala, Charlotte Jacquemont, Lluis Yedra, Vincent Humbert, Florian Godel, Bin Xu, Sergey Prosandeev, Laurent Bellaiche, Mojca Otonicar, Stephane Fusil, Brahim Dkhil, Vincent Garcia
Summary: The antiferroelectric state of 45-nm-thick epitaxial thin films of PbZrO3 is observed through the characteristic structural periodicity of dipoles and the double hysteresis of the polarization-electric field response. A transition to a ferroelectric-like state is found to occur in a large temperature window. Atomistic simulations confirm the presence and origin of the ferroelectric state in the films. Electric-field-induced ferroelectric transitions are detected via piezoresponse force microscopy.
APPLIED PHYSICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Zhonghua Dai, Fanbo Zhang, Muhammad Nasir Rafiq, Chenxi Liu, Xin Wang, Shuitao Gu, Shintaro Yasui
Summary: With the advancement of science and technology, it is important to find and develop multifunctional ceramics to meet the rapid development of electronic components. In this study, the modification of Bi(Zn0.5Ti0.5)O3 (BZT) in (K0.5Na0.5)NbO3 (KNN) has successfully improved energy storage performance and transparency under low electric field. The results show that the modified ceramic demonstrates potential applications as an energy storage and transparent capacitor in the electronics industry.
Article
Engineering, Chemical
Shohei Tada, Hiroka Kinoshita, Duanxing Li, Masahiko Nishijima, Harune Yamaguchi, Ryuji Kikcuhi, Noriko Yamauchi, Yoshio Kobayashi, Kenta Iyoki
Summary: In recent years, global warming caused by CO2 emissions has become a critical problem. In order to address this issue, a bifunctional catalyst that can convert CO2 to lower olefins in a single stage has been developed. The best performance of the catalyst was achieved when the two catalysts were mixed in close proximity.
ADVANCED POWDER TECHNOLOGY
(2023)
Article
Physics, Applied
Sou Yasuhara, Shintaro Yasui, Takuya Hoshina, Mitsuru Itoh, Takaaki Tsurumi
Summary: Epitaxial thin films have unique properties due to epitaxial strain, but the presence of defects disrupts these effects. High-temperature annealing can improve film quality, but weakens bottom electrode materials. This study focused on Nb-doped CaMnO3 as a bottom electrode to evaluate BaTiO3 ferroelectricity, demonstrating the ability to withstand high temperatures and enhance ferroelectric properties.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Pauline Dufour, Amr Abdelsamie, Johanna Fischer, Aurore Finco, Angela Haykal, Martin F. Sarott, Sara Varotto, Cecile Carretero, Sophie Collin, Florian Godel, Nicolas Jaouen, Michel Viret, Morgan Trassin, Karim Bouzehouane, Vincent Jacques, Jean-Yves Chauleau, Stephane Fusil, Vincent Garcia
Summary: Researchers have achieved the stabilization of a single-domain ferroelectric and spin cycloid state in the room-temperature magnetoelectric multiferroic BiFeO3, which is coupled to the noncollinear antiferromagnetic state. They have also discovered that anisotropic in-plane strain can be used as a powerful tool to control the antiferromagnetic state. The thickness limit of the coexisting electric and magnetic orders has been determined and the suppression of the spin cycloid induced by the magnetoelectric interaction in ultrathin films has been visualized.
Article
Chemistry, Physical
Masaru Kondo, Tatsuya Joutsuka, Kakeru Fujiwara, Tetsuo Honma, Masahiko Nishijima, Shohei Tada
Summary: In this study, we investigated the Chan-Lam cross-coupling of imidazole and arylboronic acids using heterogeneous CuO/MOX catalysts under additive-free and mild conditions. Among them, CuO/t-ZrO2 showed the best performance, with a turnover number more than ten times higher than that of bulk CuO. Experimental and computational approaches revealed that the surface structure of CuO/t-ZrO2 contained abundant highly reducible Cu2+ species, specifically square-planar [CuO4], which played a crucial role in the coupling reaction.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)