Article
Physics, Applied
Tatsuya Yamamoto, Tomohiro Ichinose, Jun Uzuhashi, Takayuki Nozaki, Tadakatsu Ohkubo, Kay Yakushiji, Shingo Tamaru, Hitoshi Kubota, Akio Fukushima, Kazuhiro Hono, Shinji Yuasa
Summary: In this study, we investigate the perpendicular magnetic anisotropy (PMA) in MgO/CoFeB (CFB)/MgO junctions by introducing an angstrom-thick Mo spacer layer. It is found that perpendicularly magnetized CFB/Mo/CFB films can be obtained for a wide range of CFB thicknesses, achieving a large PMA energy density. The voltage-controlled magnetic anisotropy effect shows a sign inversion between the 'top free' and 'bottom free' magnetic tunnel junctions, indicating the importance of the flatness of the CFB/MgO interface for improving the efficiency of the effect.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Qi Liu, Pengfei Liu, Xiaowen Li, Sixia Hu, Yuanmin Zhu, Cai Jin, Wenqiao Han, Yanjiang Ji, Zedong Xu, Songbai Hu, Mao Ye, Lang Chen
Summary: By designing and fabricating manganite-based magnetic tunnel junctions, we achieved perpendicular tunneling and observed spin-dependent tunneling behavior. The dominant role of direct tunneling was observed in the low bias region, while it was associated with thermionic emission in the high bias region.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Tatsuya Yamamoto, Takayuki Nozaki, Kay Yakushiji, Shingo Tamaru, Hitoshi Kubota, Akio Fukushima, Shinji Yuasa
Summary: The study shows that Ta layer in MgO/Ta/CoFeB/MgO junctions can enhance the PMA of magnetic films and eliminate the diffusion of Ta, leading to superior thermal stability and the release of VCMA effect. In addition, the Co-Fe compositional variation in CoFeB layer associated with Ta insertion is related to the changes in PMA and VCMA.
Article
Materials Science, Multidisciplinary
L. Gladczuk, P. Dluzewski, K. Lasek, P. Aleshkevych, D. M. Burn, G. van der Laan, T. Hesjedal
Summary: In this study, layer-resolved ferromagnetic resonance was used to investigate the coupling between the magnetic layers of a Co/MgO/Permalloy magnetic tunnel junction, showing a strong interlayer interaction through the insulating MgO barrier. A theoretical model including exchange coupling and spin pumping was developed and fits to the experimental data were compared using a likelihood ratio test, providing unambiguous proof of the existence of interlayer coupling mediated by spin pumping.
Article
Physics, Applied
S. Tacchi, F. Casoli, M. G. Pini, A. Rettori, M. Madami, J. Akerman, T. T. Le, Q. N. Pham, H. L. Pham, T. N. Anh Nguyen
Summary: Utilizing alternating gradient force magnetometry and Brillouin light scattering experiments, this study investigated perpendicular magnetic anisotropy localized at the CoFeB-MgO interface in different heterostructures. Thermal treatment was found to significantly increase the PMA, and analysis of spin wave frequencies allowed estimation of the thickness dependence of PMA in a single CoFeB film. Additionally, the study of magnetic tunnel junctions revealed an antiferromagnetic interlayer exchange coupling between CoFeB layers that increased after annealing.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Delin Zhang, Mukund Bapna, Wei Jiang, Duarte Sousa, Yu-Ching Liao, Zhengyang Zhao, Yang Lv, Protyush Sahu, Deyuan Lyu, Azad Naeemi, Tony Low, Sara A. Majetich, Jian-Ping Wang
Summary: In this study, the authors demonstrate a bipolar electric field effect switching using voltage-controlled exchange coupling, which shows potential applications in energy-efficient memory and logic devices. The results indicate that this type of switch has a lower switching current density, which could eliminate major obstacles in the development of spin memory devices.
Article
Physics, Applied
A. Sidi El Valli, V. Iurchuk, G. Lezier, I. Bendjeddou, R. Lebrun, N. Lamard, A. Litvinenko, J. Langer, J. Wrona, L. Vila, R. Sousa, I. L. Prejbeanu, B. Dieny, U. Ebels
Summary: In this study, the rectified output dc voltage of spintronic rf detectors was optimized by adjusting the properties of the magnetic tunnel junctions (MTJs). The results showed that the size and shape of the MTJ have a significant impact on the rectified signal, and reducing the diameter and thickness of the free layer can greatly enhance the rectification effect.
APPLIED PHYSICS LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Sicong Jiang, Safdar Nazir, Kesong Yang
Summary: This study presents a high-throughput screening approach to find candidate Heusler/MgO material interfaces for spintronic applications. By utilizing open quantum material repositories and conducting large-scale ab initio calculations, the researchers identified five full-Heusler compounds and two half-Heusler compounds as promising candidates for designing p-MTJs.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Physics, Applied
Furong Han, Xiaobing Chen, Jianlin Wang, Xudan Huang, Jine Zhang, Jinghua Song, Banggui Liu, Yuansha Chen, Xuedong Bai, Fengxia Hu, Baogen Shen, Jirong Sun
Summary: The research reports on the growth behavior of heterostructures formed on interfaces with symmetry mismatch, specifically focusing on the growth of La2/3Sr1/3MnO3/YBaCo2O5+delta (LSMO/YBCO) on SrTiO3. High-quality crystal structures of LSMO and YBCO were observed without any atomic rearrangement at the interface. Surprisingly, LSMO buffered by YBCO shows perpendicular magnetic anisotropy (PMA) with robust stability, even with a thin YBCO layer. This phenomenon is attributed to orbital reconstruction and the formation of a covalent bond between Mn and Co caged by different oxygen polyhedrons.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Chun- Lu, Shang-An Wang, Kristan Bryan Simbulan, Chak-Ming Liu, Xiao Wang, Guoqiang Yu, Wen-Chin Lin, Ting-Hua Lu, Yann-Wan Lan
Summary: The study demonstrates a new all-optical switching method utilizing a continuous-wave Laguerre-Gaussian beam to modify magnetic anisotropy, paving the way for the development of magnetic-based spintronics using light with orbital angular momentum.
NANOSCALE HORIZONS
(2021)
Article
Physics, Multidisciplinary
Qiuyang Li, Penghe Zhang, Haotian Li, Lina Chen, Kaiyuan Zhou, Chunjie Yan, Liyuan Li, Yongbing Xu, Weixin Zhang, Bo Liu, Hao Meng, Ronghua Liu, Youwei Du
Summary: Through experiments and simulations, it has been found that perpendicular anisotropy magnetic tunnel junctions (pMTJs) exhibit fast switching times and low write energies, and the switching time can be further reduced when the perpendicular magnetic anisotropy and damping constant of the free layer are lower within a certain range.
Article
Chemistry, Physical
Young Chan Won, Sang Ho Lim
Summary: The study investigates the perpendicular magnetic anisotropy and crystalline structure of Ta/NiFeB/MgO stacks. Annealing induces PMA and increases magnetic moment, with the thinnest 0.5-nm Ta layer showing the strongest PMA at 400 degrees Celsius. X-ray diffraction confirms the formation of NiFe (001) phase essential for high tunneling magnetoresistance ratio.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Physics, Applied
Valeria Rios-Vargas, Rodrigo Ponce-Perez, Maria G. Moreno-Armenta, Jonathan Guerrero-Sanchez
Summary: This work investigates the edge effects and spin-orbit effects on the magnetic properties of Cr2Ge2Te6 nanoribbons, and highlights their potential in spintronic device construction.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
L. Saravanan, Vireshwar Mishra, Lalit Pandey, Nanhe Kumar Gupta, Nakul Kumar, R. Gopalan, D. Prabhu, H. A. Therese, Sujeet Chaudhary
Summary: In this study, researchers achieved perpendicular magnetic anisotropy (PMA) in MgAl2O4(MAO)/CoFeMnSi(CFMS)/MgAl2O4/Ti heterostructures annealed at different temperatures and with varying CFMS layer thicknesses. The interfacial PMA was found to be highly responsive to the annealing temperature and CFMS layer thickness. Additionally, researchers observed uniaxial PMA under specific conditions. XPS analysis identified the formation of Co-O bonds at the CFMS-MAO interface as the microscopic origin of the observed PMA.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Hui-Min Tang, Shi-Zhuo Wang, Xing-Tao Jia
Summary: We conducted a first-principles study on the tunneling anisotropic magnetoresistance (TAMR) in Ag(Ir,Pt)/MgO/Fe junctions. An enhanced TAMR effect of approximately 10% was found in these junctions at the equilibrium state, exhibiting ideal and skewed fourfold angular dependence for in-plane and out-of-plane TAMR, respectively. The TAMR effect showed a simple barrier thickness dependence, with the largest effect observed in the junction with a 6-monolayer MgO barrier. The complex and enhanced TAMR effect in these junctions is believed to be attributed to interfacial states induced by spin-orbit coupling, while even a slight interfacial oxygen vacancy disorder at the Fe/MgO interface can noticeably deteriorate the TAMR effect.
Article
Physics, Multidisciplinary
Christopher Vautrin, Daniel Lacour, Coriolan Tiusan, Yuan Lu, Francois Montaigne, Mairbek Chshiev, Wolfgang Weber, Michel Hehn
Summary: In the molecular field of magnetic thin films, electronic spin precession and filtering were measured for electrons injected with energies between 0.8 and 1.1 eV. While filtering angles matched previously reported values, spin precession angles were significantly smaller at lower energies, with key roles played by band structure and layer roughness according to ab initio calculations.
ANNALEN DER PHYSIK
(2021)
Article
Physics, Applied
Christian Ortiz Pauyac, Collins Ashu Akosa, Gen Tatara, Mairbek Chshiev, Alan Kalitsov
Summary: This study investigates the thermal spin torque induced by the spin-dependent Seebeck effect in double-barrier tunnel junctions, revealing different dominant terms in thermal spin torque under different combinations of electrodes and barriers. Quantum resonant tunneling through resonance states below the Fermi level is proposed as a method to achieve higher spin-torque efficiencies.
PHYSICAL REVIEW APPLIED
(2021)
Article
Multidisciplinary Sciences
Dongxing Yu, Hongxin Yang, Mairbek Chshiev, Albert Fert
Summary: This study proposes a skyrmions-based single-nanotrack logic family that can be implemented and reconstructed by building and switching the Dzyaloshinskii-Moriya interaction (DMI) chirality barrier on a racetrack memory. The complete Boolean logic gates are realized in one single nanotrack, providing candidates for next-generation skyrmions-based logic devices and logic-in-memory applications.
NATIONAL SCIENCE REVIEW
(2022)
Article
Nanoscience & Nanotechnology
Mario Ribeiro, Giulio Gentile, Alain Marty, Djordje Dosenovic, Hanako Okuno, Celine Vergnaud, Jean-Francois Jacquot, Denis Jalabert, Danilo Longo, Philippe Ohresser, Ali Hallal, Mairbek Chshiev, Olivier Boulle, Frederic Bonell, Matthieu Jamet
Summary: In this study, we successfully grew large-area single-crystal ultrathin films of stoichiometric Fe5GeTe2 on an insulating substrate using molecular beam epitaxy. Magnetic measurements showed that the films maintained ferromagnetic properties up to room temperature, with a Curie temperature of 293 K. Surface, chemical, and structural characterizations confirmed the layer-by-layer growth, 5:1:2 Fe:Ge:Te stoichiometric composition, and single-crystalline nature of the films.
NPJ 2D MATERIALS AND APPLICATIONS
(2022)
Review
Chemistry, Multidisciplinary
Qing Hua Wang, Amilcar Bedoya-Pinto, Mark Blei, Avalon H. Dismukes, Assaf Hamo, Sarah Jenkins, Maciej Koperski, Yu Liu, Qi-Chao Sun, Evan J. Telford, Hyun Ho Kim, Mathias Augustin, Uri Vool, Jia-Xin Yin, Lu Hua Li, Alexey Falin, Cory R. Dean, Felix Casanova, Richard F. L. Evans, Mairbek Chshiev, Artem Mishchenko, Cedomir Petrovic, Rui He, Liuyan Zhao, Adam W. Tsen, Brian D. Gerardot, Mauro Brotons-Gisbert, Zurab Guguchia, Xavier Roy, Sefaattin Tongay, Ziwei Wang, M. Zahid Hasan, Joerg Wrachtrup, Amir Yacoby, Albert Fert, Stuart Parkin, Kostya S. Novoselov, Pengcheng Dai, Luis Balicas, Elton J. G. Santos
Summary: Research on magnetism in 2D van der Waals materials has shown exciting potential for future applications, although challenges remain. It provides important theoretical foundations and guidance for future applications.
Article
Physics, Applied
Fatima Ibrahim, Ali Hallal, Alan Kalitsov, Derek Stewart, Bernard Dieny, Mairbek Chshiev
Summary: This work theoretically addresses the correlation between the temperature dependence of magnetic anisotropy and magnetization in Fe/MgO-based structures. The study reveals possible intrinsic and extrinsic mechanisms that can explain deviations from the Callen and Callen scaling power law. These findings have implications for understanding the thermal stability of storage-layer magnetization in STT-MRAM applications.
PHYSICAL REVIEW APPLIED
(2022)
Article
Nanoscience & Nanotechnology
Jayshankar Nath, Alexandru Vladimir Trifu, Mihai Sebastian Gabor, Ali Hallal, Stephane Auffret, Sebastien Labau, Aymen Mahjoub, Edmond Chan, Avinash Kumar Chaurasiya, Amrit Kumar Mondal, Haozhe Yang, Eva Schmoranzerova, Mohamed Ali Nsibi, Isabelle Joumard, Anjan Barman, Bernard Pelissier, Mairbek Chshiev, Gilles Gaudin, Ioan Mihai Miron
Summary: In Spin-Orbit Torque (SOT) Magnetic Random-Access Memories (MRAM), oxidation of the heavy-metal (HM) layer has been proposed to increase energy efficiency. By gradually oxidizing the stack, systemic changes and the presence of an oxide inversion layer are found.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Multidisciplinary Sciences
Hyunsoo Yang, Sergio O. Valenzuela, Mairbek Chshiev, Sebastien Couet, Bernard Dieny, Bruno Dlubak, Albert Fert, Kevin Garello, Matthieu Jamet, Dae-Eun Jeong, Kangho Lee, Taeyoung Lee, Marie-Blandine Martin, Gouri Sankar Kar, Pierre Seneor, Hyeon-Jin Shin, Stephan Roche
Summary: This article provides an overview of the current developments and challenges in regards to MRAM and outlines the opportunities that can arise by incorporating two-dimensional material technologies. The fundamental properties of atomically smooth interfaces, reduced material intermixing, crystal symmetries, and proximity effects are highlighted as key drivers for possible disruptive improvements in MRAM at advanced technology nodes.
Article
Nanoscience & Nanotechnology
Zhengwei Tan, Sofia Martins, Michael Escobar, Julius de Rojas, Fatima Ibrahim, Mairbek Chshiev, Alberto Quintana, Aitor Lopeandia, Jose L. Costa-Kramer, Enric Menendez, Jordi Sort
Summary: Magneto-ionics is an emerging actuation mechanism to control the magnetic properties of materials via voltage-driven ion motion. This study demonstrates that the introduction of suitable transition-metal elements to binary nitride compounds can significantly enhance the magneto-ionic effects. By substituting 10% of Co with Mn in CoN films, the saturation magnetization, toggling speeds, and cyclability of the films can be drastically improved. These findings provide a fundamental understanding of the crucial role of Mn addition in voltage-driven magnetic effects and pave the way for enhanced voltage control of magnetism via electric field-driven ion motion.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Jinghua Liang, Mairbek Chshiev, Albert Fert, Hongxin Yang
Summary: In this study, we used atomistic spin calculations to investigate an intriguing type of Dzyaloshinskii-Moriya interaction (DMI) that emerges in films with composition gradient. We found that the strength and chirality of this DMI can be controlled by the composition gradient, even in disordered systems. Our study also demonstrated the DMI-induced chiral magnetic structures and field-free spin-orbit torque switching, both of which are crucial for practical device applications.
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
Quentin Guillet, Libor Vojacek, Djordje Dosenovic, Fatima Ibrahim, Herve Boukari, Jing Li, Fadi Choueikani, Philippe Ohresser, Abdelkarim Ouerghi, Florie Mesple, Vincent Renard, Jean-Francois Jacquot, Denis Jalabert, Hanako Okuno, Mairbek Chshiev, Celine Vergnaud, Frederic Bonell, Alain Marty, Matthieu Jamet
Summary: In this study, five-monolayer quasifreestanding Cr2Te3 films were successfully grown on three classes of 2D materials (graphene, WSe2, and Bi2Te3) using molecular beam epitaxy. The films exhibited strong magnetism and high Curie temperature, with sharp van der Waals interfaces. The strength of the magnetism was found to be tunable by strain.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Physics, Multidisciplinary
Albert Fert, Mairbek Chshiev, Andre Thiaville, Hongxin Yang
Summary: Since the early 1960's, the discovery of Dzyaloshinskii-Moriya interaction (DMI) has explained various magnetic phenomena and gained increasing interest for its role in stabilizing magnetic domain walls and magnetic skyrmions. DMI is governed by spin-orbit coupling (SOC) and inversion symmetry breaking (ISB), leading to distinct morphologies of magnetic skyrmions. This research aims to introduce the history of DMI and its significance in the field of modern spintronics.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Materials Science, Multidisciplinary
Ziji Shao, Jinghua Liang, Qirui Cui, Mairbek Chshiev, Albert Fert, Tiejun Zhou, Hongxin Yang
Summary: Using first-principles calculations, it was found that nonmetallic bilayer transition-metal dichalcogenides can serve as an ideal platform for building two-dimensional multiferroics, and electric-field control of the chirality of topological magnetic objects can be achieved in this type of materials.
Article
Engineering, Electrical & Electronic
Emilio Velez-Fort, Ali Hallal, Roberto Sant, Thomas Guillet, Khasan Abdukayumov, Alain Marty, Celine Vergnaud, Jean-Francois Jacquot, Denis Jalabert, Jun Fujii, Ivana Vobornik, Julien Rault, Nicholas B. Brookes, Danilo Longo, Philippe Ohresser, Abdelkarim Ouerghi, Jean-Yves Veuillen, Pierre Mallet, Herve Boukari, Hanako Okuno, Mairbek Chshiev, Frederic Bonell, Matthieu Jamet
Summary: We report on a two-dimensional alloy V1-xPtxSe2 that exhibits ferromagnetic order and Rashba spin-orbit coupling. By substituting vanadium with platinum in VSe2, we restore ferromagnetic order down to one monolayer of V0.65Pt0.35Se2. Moreover, the presence of platinum atoms gives rise to Rashba spin-orbit coupling in (V,Pt)Se2, providing an original platform to study the interplay between ferromagnetism and spin-orbit coupling in the 2D limit.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
