Article
Multidisciplinary Sciences
Dacen Waters, Ellis Thompson, Esmeralda Arreguin-Martinez, Manato Fujimoto, Yafei Ren, Kenji Watanabe, Takashi Taniguchi, Ting Cao, Di Xiao, Matthew Yankowitz
Summary: Moire patterns formed by stacking twisted atomically thin van der Waals crystals can modify the electronic properties of bulk graphitic thin films in a dual-gated device. At zero and small magnetic fields, transport is mediated by gate-tuneable moire and graphite surface states, as well as coexisting semimetallic bulk states. At high field, the moire potential hybridizes with the graphitic bulk states, creating a single quasi-two-dimensional hybrid structure. This study establishes twisted graphene-graphite as a new class of mixed-dimensional moire materials.
Article
Chemistry, Physical
Wen-Bin Wu, Julia Kasiuk, Janusz Przewoznik, Czeslaw Kapusta, Ivan Svito, Dang Thanh Tran, Hung Manh Do, Hung Manh Dinh, Johan Akerman, Thi Ngoc Anh Nguyen
Summary: We studied the magnetoresistance mechanisms in a Pt/[Co/Pt]x5 film consisting of a ferromagnetic [Co/Pt]x5 layer with strong perpendicular magnetic anisotropy and a nonmagnetic Pt layer with strong spin-orbit coupling. Two competing contributions, sin2 theta and cos4 theta, were revealed in the electrical resistance of the film at different angles and magnetic fields, corresponding to the out-of-plane rotation of the magnetization M(theta) perpendicularly to the electric current. The cos4 theta contribution is attributed to the anisotropic magnetoresistance of the ferromagnetic layer, while the sin2 theta contribution is mainly associated with the spin Hall magnetoresistance originating from the Pt layer. The strong influence of the electric current on the magnetization of the film is of high relevance for magnetic memory design technologies.
APPLIED SURFACE SCIENCE
(2024)
Article
Physics, Applied
Yu Miao, Dezheng Yang, Lei Jia, Xiaolin Li, Shuanglong Yang, Cunxu Gao, Desheng Xue
Summary: This study reports on the magnetoresistance in different crystallographic directions of epitaxial ferromagnetic Fe30Co70 thin films with magnetization rotated in the film plane. The findings can be explained by a magnetocrystalline anisotropy (MCA) symmetry-adapted model, where the MCA-dependent twofold term contributes to the negative SCAMR. This research provides insights on understanding and designing magnetoresistance with ferromagnets by MCA.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
R. S. Mrinaleni, E. P. Amaladass, A. T. Sathyanarayana, S. Amirthapandian, P. Jegadeesan, Pooja Gupta, T. Geetha Kumary, S. K. Rai, Awadhesh Mani
Summary: We investigated the magnetic and magnetotransport properties of nanostructured Nd0.6Sr0.4MnO3 (NSMO) thin films grown on (100) oriented SrTiO3 (STO) substrates. The results showed that the surface morphology of the thin films has a significant impact on their magnetic and magnetotransport properties. Thin films with a rod-type morphology exhibited improved in-plane magnetic anisotropy and enhanced anisotropic magnetoresistance ratio (AMR) around their metal-insulator transition temperature. Such morphology-dependent tunability in magnetoresistance properties is potentially interesting for developing oxide-based sensors and devices.
Article
Engineering, Electrical & Electronic
Lulu Cao, Qingjie Guo, Jian Liang, Zhaoxia Kou, Xiaochao Zhou, Zhaocong Huang, Ya Zhai, Jun Du, Biao You, Huihui Zhao, Qi Li, Wen Zhang, Andrew Thye Shen Wee, Ping Kwan Johnny Wong, Xiaojiang Yu
Summary: Fe3O4 film was grown on Si (100) substrates by sputtering without oxygen atmosphere at various temperatures, followed by heat treatments. The structure and magnetic moment of the film were found to be influenced by both the growth temperature and post-heat treatment temperature, leading to a method for fabricating high magnetic moment Fe3O4 thin films.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Nanoscience & Nanotechnology
Ryo Toyama, Varun K. Kushwaha, Taisuke T. Sasaki, Yuma Iwasaki, Tomoya Nakatani, Yuya Sakuraba
Summary: In this study, a high-throughput compositional optimization method for high spin polarization in Co-2(Mn, Fe)Ge Heusler alloys is demonstrated. By combining composition-spread films and anisotropic magnetoresistance (AMR) measurement, the composition dependence of AMR and spin polarization is investigated. The results show that the highest spin polarization can be achieved at specific composition ratios.
Article
Nanoscience & Nanotechnology
Yutao Li, Scott Dietrich, Carlos Forsythe, Takashi Taniguchi, Kenji Watanabe, Pilkyung Moon, Cory R. Dean
Summary: By utilizing dielectric patterning to subject graphene to a one-dimensional electrostatic superlattice, multiple Dirac cones are observed, demonstrating the ability to induce tunable anisotropy in high-mobility two-dimensional materials. This offers a new approach to engineering flat energy bands where electron interactions can lead to emergent properties, which is desired for novel electronic and optical applications.
NATURE NANOTECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Xiaojun Yang, Junxiao Pan, Weizhuo Gai, Yaping Tao, Hong Jia, Leiming Cao, Yan Cao
Summary: The critical properties and magnetic entropy change of quasi-two-dimensional LaCrSb3 single crystals were systematically investigated. The critical exponents indicate a three-dimensional critical behavior and the magnetic entropy change exhibits strong anisotropic features.
Article
Physics, Applied
Andrew W. Forbes, Niraj Bhattarai, Christopher Gassen, Raghad S. H. Saqat, Ian L. Pegg, John Philip
Summary: Thin films of ferromagnet Fe2Ge were successfully grown via molecular beam epitaxy, and their magnetic and electrical properties were measured experimentally. The material showed strong spin polarization, as indicated by the observed high-temperature maximum in the longitudinal resistivity and the suppression of electron-magnon scattering at low temperatures. Measurements of the Hall resistivity revealed contributions from both the ordinary and anomalous Hall effects, providing information about the charge carrier concentration and mobility. Additionally, small negative magnetoresistance was observed in both longitudinal and transverse geometries. Fe2Ge holds promise as a spintronic material due to its compatibility with semiconductors.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Zhao-Cai Wang, Lei Chen, Shuang-Shuang Li, Jing-Shi Ying, F. Tang, Guan-Yin Gao, Y. Fang, Weiyao Zhao, David Cortie, Xiaolin Wang, Ren-Kui Zheng
Summary: Linear magnetoresistance (LMR) is observed in half-metallic perovskite Sr2CrMoO6 thin films, with a maximum MR value exceeding +1600%, possibly due to high carrier density and ultrahigh mobility. This unusual behavior in ferrimagnetic double perovskite materials may broaden the applications of perovskites and stimulate research on metallic oxide ferri-/ferro-magnetic materials.
NPJ QUANTUM MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Vinay Sharma, Rajeev Nepal, Ramesh C. Budhani
Summary: This research reports on magnetotransport measurements of Mn3Sn thin films grown on single-crystal MgO substrates. The films exhibit weak magnetism and resistivity at room temperature, and different magnetic phases at different temperatures, revealing the effects of topologically protected spin textures.
Article
Materials Science, Multidisciplinary
Kevin Booth, Isaiah Gray, E. Dan Dahlberg
Summary: The differential AC magnetic susceptibility of thin magnetic films was found to depend on the magnitude of the DC field and decrease with increasing frequency.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Physics, Applied
Fan Yu, Yuling Yin, Gan Liu, Qichao Tian, Qinghao Meng, Wenhua Zhao, Kaili Wang, Can Wang, Shaoguang Yang, Di Wu, Xiangang Wan, Yi Zhang
Summary: In this study, the molecular beam epitaxial growth of atomically flat chromium telluride (CrTex) films on Si substrates was achieved in the two-dimensional limit. A thickness-dependent structural phase transition and self-intercalation during the growth were discovered. The ferromagnetism in the chromium telluride film down to one layer limit was confirmed. These findings provide valuable insights for studying the structural phase transition and ferromagnetism in 2D systems, and contribute to the further applications of 2D ferromagnetic films.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
V. V. Balashev, K. S. Ermakov, D. A. Tsukanov, A. Yu. Samardak, A. V. Ognev, A. S. Samardak
Summary: This study investigates the influence of magnetite film thickness on its electrical, magnetic, and magnetotransport properties. It is found that the saturation magnetization increases nonmonotonically with film thickness, reaching its maximum at 170 nm. Films with a thickness of more than 150 nm show a significant decrease in resistivity, while the lowest coercive force is observed at a film thickness of 100 nm. The magnetoresistance value reaches -2.5% at a thickness of 50 nm and remains almost unchanged with further increase in the thickness of the textured film. The textured-F3O4/SiO2/n-Si(001) junction with amorphous SiO2 barrier shows promise for Si-based spintronic devices.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
A. Peltonen, J. Etula, J. Seitsonen, P. Engelhardt, T. Laurila
Summary: This study utilized various techniques to investigate the microstructure of Nafion thin films. The results showed that film thickness affects the relative proportions of hydrophobic and hydrophilic regions within the polymer, while the channel diameter and spacing between hydrophilic channels also display certain relationships.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Xi Shen, Haoran Chen, Yi Li, Hong Xia, Fanlong Zeng, Jia Xu, Hee Young Kwon, Yi Ji, Changyeon Won, Wei Zhang, Yizheng Wu
Summary: The magnetization dynamics of CrI3 and CrBr3 were investigated using broadband ferromagnetic resonance (FMR) techniques, revealing the significant influence of multi-domain structures on the magnetic dynamics properties. Additionally, the linewidths of FMR spectra in CrI3 and CrBr3 were found to be dominated by magnetic inhomogeneous broadening.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Physics, Multidisciplinary
Zhong Shi, Qing Xi, Junxue Li, Yufei Li, Mohammed Aldosary, Yadong Xu, Jun Zhou, Shi-Ming Zhou, Jing Shi
Summary: The spin Seebeck effect (SSE) signal of magnon polarons in bulk-Y3Fe5O12 (YIG)/Pt heterostructures shows a transition from a dip to a peak as temperature increases, attributed to the rapid rise of the four-magnon scattering rate. This analysis offers important insights into the microscopic origin of hybridized excitations and the overall temperature dependence of SSE anomalies.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Victor H. Ortiz, Bassim Arkook, Junxue Li, Mohammed Aldosary, Mason Biggerstaff, Wei Yuan, Chad Warren, Yasuhiro Kodera, Javier E. Garay, Igor Barsukov, Jing Shi
Summary: The static and dynamic properties of magnetic insulator thin films are crucial for spintronic device applications. By controlling the lattice mismatch between EuIG thin films and substrates, the strain in the films can be tuned, affecting their magnetic behavior. Research shows that the linewidth of ferromagnetic resonance increases significantly with strain, while the perpendicular magnetic anisotropy exhibits both first and second-order effects in response to strain.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Physics, Multidisciplinary
Jia Xu, Jing Xia, Xichao Zhang, Chao Zhou, Dong Shi, Haoran Chen, Tong Wu, Qian Li, Haifeng Ding, Yan Zhou, Yizheng Wu
Summary: We experimentally demonstrate that the switching rate of the antiferromagnetic (AFM) domain can be significantly enhanced by more than 2 orders of magnitude through applying an alternating square-wave field on a Fe/CoO bilayer. This finding opens up new opportunities for designing antiferromagnet-based spintronic devices.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Gong Chen, Colin Ophus, Alberto Quintana, Heeyoung Kwon, Changyeon Won, Haifeng Ding, Yizheng Wu, Andreas K. Schmid, Kai Liu
Summary: In this study, a novel approach of using hydrogen adsorption for writing and deleting skyrmions at room temperature was demonstrated. Through Monte-Carlo simulations, it was found that hydrogen-induced magnetic anisotropy change led to the creation and annihilation of skyrmions. Additionally, the effects of hydrogen and oxygen on magnetic anisotropy and skyrmion deletion on other magnetic surfaces were also explored.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Hong Xia, Haoran Chen, Changyeon Won, Haibin Zhao, Yizheng Wu
Summary: In this study, we investigated the propagation and emission of spin waves (SWs) in thin film systems with strong interfacial Dzyaloshinskii-Moriya interaction (DMI) using micromagnetic simulation. We found that DMI affects the propagation of SWs in a way analogous to the spin Doppler effect caused by the flow of magnetic medium, and this effect can be enhanced or suppressed by a spin-polarized current. Furthermore, by combining the interfacial DMI and the spin-polarized current, we demonstrated a continuous emission of SWs from a static source, providing a promising approach to generate SWs with tunable frequency.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Multidisciplinary Sciences
Junxue Li, Mina Rashetnia, Mark Lohmann, Jahyun Koo, Youming Xu, Xiao Zhang, Kenji Watanabe, Takashi Taniguchi, Shuang Jia, Xi Chen, Binghai Yan, Yong-Tao Cui, Jing Shi
Summary: Van der Waals heterostructures allow for integration of different materials with distinct properties, leading to novel physical phenomena. In this study, Li et al combine a quantum spin hall insulator, WTe2, with an insulating ferromagnet, Cr2Ge2Te6, resulting in induced magnetism in the WTe2 layer and anomalous Hall and Nernst effects. The proximity-induced ferromagnetic order in WTe2 manifests in various transport phenomena, and spin-polarized edge states are revealed in the magnetized quantum spin hall insulator.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Applied
Yawen Liu, Haoyu Liu, Wei Yuan, Yuhang Li, Junxue Li, Qiming Shao, Ran Cheng, Jing Shi
Summary: This study demonstrates highly efficient control of antiferromagnetic (AFM) magnon spins in heterostructures of yttrium iron garnet (YIG) and Cr2O3. By the interfacial exchange interaction exerted by YIG, the degeneracy between the AFM magnon modes in Cr2O3 is lifted, resulting in controlled spin polarization and spin current.
PHYSICAL REVIEW APPLIED
(2022)
Article
Chemistry, Multidisciplinary
Shunjia Wang, Wentao Qin, Sheng Zhang, Yuchen Lou, Changqin Liu, Tong Wu, Qiong He, Chuanshan Tian, Lei Zhou, Yizheng Wu, Zhensheng Tao
Summary: In this work, the authors demonstrate the realization of multifunctional spintronic-metasurface emitters, which allow simultaneous beam-steering and full polarization control of terahertz waves. The nanoengineered metasurface enables flexible control over the terahertz beam's spatial distribution and polarization states, offering a solution to the challenges associated with the growing variety of terahertz technology applications.
Article
Physics, Applied
J. He, Z. R. Zhao, H. Xia, T. Li, E. Liang, G. Ni, J. Wang, C. X. Sheng, L. Y. Chen, Y. Z. Wu, H. B. Zhao
Summary: We investigate the modulation of interlayer exchange coupling (IEC) between ferromagnet (FM) Fe and insulating antiferromagnet (AFM) CoO and its effect on Gilbert damping using a time-resolved magneto-optical Kerr effect technique. Inserting a wedge spin conductor Ag layer at the Fe/CoO interface reveals that the precession frequency and damping of the Fe film decrease with increasing Ag thickness, reaching intrinsic values above 2 nm where IEC is eliminated. The temperature dependence of the precession frequency and damping also follows a similar trend for attenuated IEC. These findings emphasize the crucial role of exchange coupling at the FM-AFM interface in spin angular momentum transfer and suggest implications for spintronic applications.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Hongyue Xu, Haoran Chen, Fanlong Zeng, Jia Xu, Xi Shen, Yizheng Wu
Summary: We investigated the anisotropy of Gilbert damping in Co-Fe-B(001) films and found a clear four-fold symmetry with respect to the in-plane field orientation. The maximum damping was observed for the field along Co-Fe-B(100). The anisotropic magnetoresistance (AMR) in the films showed little current-orientation dependence, indicating weak correlation with the origin of damping anisotropy. This research provides a useful way to control intrinsic damping for designing and optimizing spintronics devices based on Co-Fe-B.
PHYSICAL REVIEW APPLIED
(2023)
Article
Nanoscience & Nanotechnology
Chao Zhou, Jia Xu, Tong Wu, Yizheng Wu
Summary: Antiferromagnets, with high stability and stray-field-free property, are considered as a promising host material for the next generation of magnetic storage. However, conventional magnetometry becomes ineffective in investigating their microscopic properties due to the absence of net magnetization. In this Perspective, an overview of various antiferromagnetic domain imaging techniques is provided, with a focus on the promising optical imaging method based on the magneto-optical birefringence effect. Recent advances in imaging antiferromagnetic domains using the magneto-optical birefringence technique are highlighted.
Article
Materials Science, Multidisciplinary
Xi Shen, Haoran Chen, Dong Shi, Hong Xia, Jia Xu, Fanlong Zeng, Yizheng Wu
Summary: The study investigates magnetization dynamics in disconnected kagome artificial spin ice (ASI) lattices using experimental and theoretical approaches. The research identifies the dynamical coupling effects and special magnon modes in different field orientations. This contributes to a better understanding of collective spin-dynamics behavior in nanomagnet systems.
Article
Materials Science, Multidisciplinary
Xingyu Shen, Yunjiao Cai, Yizheng Wu, Yi Ji
Summary: The ability to tune the spin relaxation length in mesoscopic Cu channels using ionic gating technique has been explored, showing reversibility at low temperature and room temperature. The tuning range can be gradually amplified through repeated gate voltage cycling.
Article
Materials Science, Multidisciplinary
Gang Qin, Xichao Zhang, Ruixuan Zhang, Ke Pei, Chendi Yang, Chunyang Xu, Yan Zhou, Yizheng Wu, Haifeng Du, Renchao Che
Summary: We experimentally demonstrate the reversible motion of skyrmions driven by a controlled temperature gradient in a chiral magnet FeGe. The skyrmions show directional thermal diffusion along the gradient of temperature, indicating the thermal-induced skyrmion Hall effect. Our results provide a promising way for the realization of caloritronic applications based on topological spin textures.
