Article
Materials Science, Multidisciplinary
Hongyu Chen, Zexin Feng, Han Yan, Peixin Qin, Xiaorong Zhou, Huixin Guo, Xiaoning Wang, Haojiang Wu, Xin Zhang, Ziang Meng, Zhiqi Liu
Summary: Unexpected weak anomalous Hall effect was found in polycrystalline thin films of chromium, possibly attributed to noncollinear spin textures induced by local spin frustration and rearrangement. A dominant intrinsic Berry phase mechanism is speculated. This may be a general feature for collinear antiferromagnetic thin-film materials with moderately high defect concentrations, making them promising candidates for emergent antiferromagnetic spintronics.
Article
Chemistry, Physical
B. F. Malvasio, L. M. Isola, M. F. Giordana, J. A. Malarria
Summary: In this study, Ti-rich NiTiCo thin films were produced and annealed at different temperatures to investigate their microstructures and shape memory behavior. It was found that the sample annealed at 773 K exhibited Guinier-Preston (GP) zones, while Ti2Ni precipitates were observed in the samples annealed at 873 K and 973 K. A higher recoverable strain and negligible irreversible strain were observed in the 773 K annealed sample compared to the others.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Physics, Multidisciplinary
Junya Ikeda, Kohei Fujiwara, Junichi Shiogai, Takeshi Seki, Kentaro Nomura, Koki Takanashi, Atsushi Tsukazaki
Summary: This study investigates the bulk and surface conduction channels of the Weyl semimetal Co3Sn2S2, showing the emergence of a 2D conducting channel in thin films under the ferromagnetic phase. The comparison between 3D conductivity and 2D conductance reveals an effective thickness of approximately 20nm for the surface conducting region, reflecting the Weyl feature of electronic bands in Co3Sn2S2.
COMMUNICATIONS PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Hanna Bishara, P. Kontis, Gerhard Dehm, Jochen M. Schneider, Simon Evertz
Summary: The relationship between the fraction of hybridized bonds and the electrical behavior in thin film metallic glasses has been investigated. It was found that strong bond hybridization leads to high resistivity, while weak bond hybridization results in lower resistivity.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Ryo Toyama, Satoshi Kokado, Keisuke Masuda, Zehao Li, Varun K. Kushwaha, Taisuke T. Sasaki, Loku Singgappulige Rosantha Kumara, Tomoyuki Koganezawa, Hiroo Tajiri, Takahiro Yamazaki, Masato Kotsugi, Yuma Iwasaki, Yuya Sakuraba
Summary: In this paper, the origin of the anisotropic magnetoresistance (AMR) effect in thin films is investigated through experimental observation and theoretical modeling. It is found that the addition of Ir atoms leads to a sign change in the AMR ratio, with the highest negative values observed at high Ir concentrations. The theoretical model confirms that this sign change is due to the B2 ordering phase. These findings provide insights into the AMR origin in heavy-metal-doped ferromagnetic alloys.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Weiwei Wu, Jinfeng Li, Zhiyu Liao, Hongyu Jiang, Laiquan Shen, Lin Gu, Xianggang Qiu, Yugui Yao, Haiyang Bai
Summary: The study reveals the linear dependence of anomalous Hall conductivity on magnetization in ferromagnetic metallic glasses, which indicates intrinsic mechanism contribution. Additionally, the influence of Berry curvature density and spin orientation fluctuations on the anomalous Hall effect is also highlighted.
Article
Materials Science, Multidisciplinary
Dongwon Shin, Soon-Gil Jung, Sehun Seo, Jongmin Lee, Sanghan Lee, Jin Hee Kim, Jong-Soo Rhyee, Woo Seok Choi, Tuson Park
Summary: This study investigates the scaling behavior between Hall resistivity (pxy) and longitudinal resistivity (pxx) in FeSe0.7Te0.3 (FST) thin films, and explores the influence of different beta values on the vortex liquid state in FST thin films.
Article
Materials Science, Coatings & Films
Florian Lourens, Alfred Ludwig
Summary: This method presents a way to uniformly deposit thin films on microparticles by oscillating them, allowing for the coating of different types of particles and the deposition of films with composition gradients on uniform particles.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
R. S. Nair, M. S. Rang, Paul J. Kelly
Summary: A density-functional-theory-based relativistic scattering formalism was used to study charge transport through thin Pt films with room-temperature lattice disorder. The research found that a Fuchs-Sondheimer specularity coefficient is needed to describe the suppression of charge current at the surface, even in the absence of surface roughness. It was also discovered that the spin Hall effect is substantially enhanced at the surface, with a reduced value of the spin Hall angle.
Article
Multidisciplinary Sciences
Yunhe Bai, Yuanzhao Li, Jianli Luan, Ruixuan Liu, Wenyu Song, Yang Chen, Peng-Fei Ji, Qinghua Zhang, Fanqi Meng, Bingbing Tong, Lin Li, Yuying Jiang, Zongwei Gao, Lin Gu, Jinsong Zhang, Yayu Wang, Qi-Kun Xue, Ke He, Yang Feng, Xiao Feng
Summary: This study realized quantized anomalous Hall resistivity in MBE-grown MnBi2Te4 thin films by controlling the chemical potential and top gating. Post-annealing can increase the temperature for quantization but also increase the residual longitudinal resistivity.
NATIONAL SCIENCE REVIEW
(2023)
Article
Chemistry, Physical
P. V. Karthik Yadav, B. Ajitha, Y. Ashok Kumar Reddy, Vasudeva Reddy Minnam Reddy, Maddaka Reddeppa, Moon-Deock Kim
Summary: Tungsten trioxide (WO3) deposited at 10 mTorr sputter pressure demonstrated high sensitivity and external quantum efficiency (EQE) for UV photodetector applications. The effect of sputter pressure on the crystallinity, morphology, and photodetector performance of WO3 films was studied, showing that films deposited at 10 mTorr had higher crystallinity and surface roughness, making them suitable for UV photodetector applications.
APPLIED SURFACE SCIENCE
(2021)
Article
Physics, Applied
H. Richter, W. Lang, M. Peruzzi, H. Hattmansdorfer, J. H. Durrell, J. D. Pedarnig
Summary: Thin films of high-temperature superconductor HgBa2CaCu2O6 were prepared on SrTiO3 substrates by pulsed-laser deposition and annealing in a mercury-vapor atmosphere. The microstructural properties were analyzed by X-ray analysis and atomic force microscopy, showing similar superconducting properties despite morphological variations. Hall measurements provided estimates of carrier scattering defects and vortex pinning properties inside the grains in the superconducting state.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Michael K. Steinhoff, Damian M. Holzapfel, Soheil Karimi Aghda, Deborah Neuss, Peter J. Poellmann, Marcus Hans, Daniel Primetzhofer, Jochen M. Schneider, Clio Azina
Summary: Ag-containing ZrCuAlNi thin film metallic glass (nano)composites were prepared using a hybrid sputtering process, and the effects of Ag content, substrate temperature, and substrate bias potential on the phase formation and morphology of the composites were investigated.
Article
Materials Science, Multidisciplinary
Yinong Yin, Ashutosh Tiwari
Summary: The performance of spin thermoelectric devices composed of Ta100-xCux/YIG films was investigated, with the Ta97Cu3/YIG system showing the best thermoelectric response, five times higher than undoped Ta/YIG.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2021)
Article
Physics, Condensed Matter
Denis Dyck, Andreas Becker, Jungwoo Koo, Tristan Matalla-Wagner, Jan Krieft, Guenter Reiss
Summary: The investigation on sputter-deposited ferromagnetic Weyl semimetal (WSM) and full-Heusler compound Co2TiGe shows formation of L2(1) crystal structure, close agreement of magnetization measurements with calculated values, a Curie temperature of 378.5 K, and domination of Coulomb interaction in resistance above 60 K. The Hall measurements indicate positive ordinary Hall and anomalous Hall constants, as well as a positive dependence on temperature. Skew scattering and intrinsic mechanisms contribute to the anomalous Hall resistivity, reflecting a higher than usual intrinsic contribution expected for WSMs. However, the expected relation between the longitudinal and the anomalous Hall conductivity is not met.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
E. Georgopoulou-Kotsaki, P. Pappas, A. Lintzeris, P. Tsipas, S. Fragkos, A. Markou, C. Felser, E. Longo, M. Fanciulli, R. Mantovan, F. Mahfouzi, N. Kioussis, A. Dimoulas
Summary: The 2D van der Waals ferromagnetic metals FexGeTe2 with x = 3-5 have attracted significant attention. In this study, epitaxial Fe5-dGeTe2 (FGT) heterostructures were grown on insulating crystalline substrates using Molecular Beam Epitaxy (MBE). The addition of Bi2Te3 topological insulator (TI) to FGT films significantly enhanced the saturation magnetization and Curie temperature (Tc), with record values of 570 K obtained.
Article
Physics, Multidisciplinary
Daniel S. S. Sanchez, Tyler A. A. Cochran, Ilya Belopolski, Zi-Jia Cheng, Xian P. Yang, Yiyuan Liu, Tao Hou, Xitong Xu, Kaustuv Manna, Chandra Shekhar, Jia-Xin Yin, Horst Borrmann, Alla Chikina, Jonathan D. D. Denlinger, Vladimir N. N. Strocov, Weiwei Xie, Claudia Felser, Shuang Jia, Guoqing Chang, M. Zahid Hasan
Summary: The classification of electronic phases is based on two prominent paradigms: correlations and topology. Electron correlations lead to superconductivity and charge density waves, while the Berry phase gives rise to electronic topology. The combination of these two paradigms has prompted the search for electronic instabilities near the Fermi level of topological materials. This study identifies the electronic topology of chiral fermions as the driving force behind van Hove singularities that host electronic instabilities in the surface band structure.
Article
Physics, Multidisciplinary
Belen E. Zuniga-Cespedes, Kaustuv Manna, Hilary M. L. Noad, Po-Ya Yang, Michael Nicklas, Claudia Felser, Andrew P. Mackenzie, Clifford W. Hicks
Summary: By applying a combination of uniaxial stress and magnetic field, we have observed a significant anomalous Hall effect in a bulk sample of a cubic member of the Mn3X family for the first time. The observed effect remains unchanged when the stress is removed, indicating that it is not induced by stress-induced ferromagnetic moments.
NEW JOURNAL OF PHYSICS
(2023)
Article
Physics, Multidisciplinary
Tyler A. Cochran, Ilya Belopolski, Kaustuv Manna, Mohammad Yahyavi, Liu Yiyuan, Daniel S. Sanchez, Cheng Zi-Jia, Xian P. Yang, Daniel Multer, Yin Jia-Xin, Horst Borrmann, Alla Chikina, Jonas A. Krieger, Jaime Sanchez-Barriga, Patrick Le Fevre, Francois Bertran, Vladimir N. Strocov, Jonathan D. Denlinger, Chang Tay-Rong, Jia Shuang, Claudia Felser, Hsin Lin, Chang Guoqing, M. Zahid Hasan
Summary: In this Letter, the authors discovered the higher-fold topology of a chiral crystal using a combination of fine-tuned chemical engineering and photoemission spectroscopy. They identified all bulk branches of a higher-fold chiral fermion and revealed a multigap bulk boundary correspondence. This demonstration of multigap electronic topology will drive future research on unconventional topological responses.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Chunyu Guo, A. Alexandradinata, Carsten Putzke, Amelia Estry, Teng Tu, Nitesh Kumar, Feng-Ren Fan, Shengnan Zhang, Quansheng Wu, Oleg V. Yazyev, Kent R. Shirer, Maja D. Bachmann, Hailin Peng, Eric D. Bauer, Filip Ronning, Yan Sun, Chandra Shekhar, Claudia Felser, Philip J. W. Moll
NATURE COMMUNICATIONS
(2023)
Correction
Multidisciplinary Sciences
Yudi Zhang, Kathryn E. Arpino, Qun Yang, Naoki Kikugawa, Dmitry A. Sokolov, Clifford W. Hicks, Jian Liu, Claudia Felser, Guowei Li
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Subhajit Roychowdhury, Mengyu Yao, Kartik Samanta, Seokjin Bae, Dong Chen, Sailong Ju, Arjun Raghavan, Nitesh Kumar, Procopios Constantinou, Satya N. Guin, Nicholas Clark Plumb, Marisa Romanelli, Horst Borrmann, Maia G. Vergniory, Vladimir N. Strocov, Vidya Madhavan, Chandra Shekhar, Claudia Felser
Summary: In this study, the electronic structure of ferromagnetic EuCd2As2, predicted to be an ideal Weyl semimetal, is investigated using angle-resolved photoemission spectroscopy and scanning tunneling microscopy. The experimental results are in close agreement with the first principles calculations. Furthermore, anomalous Hall conductivity and Nernst effect are observed, resulting from the non-zero Berry curvature and the topological Hall effect arising from changes in the band structure caused by spin canting produced by magnetic fields. These findings provide insights into exotic quantum phenomena in inorganic topological materials with multiple pairs of Weyl nodes.
Article
Materials Science, Multidisciplinary
Hua Lv, Edouard Lesne, Rebeca Ibarra, Yan Sun, Anastasios Markou, Claudia Felser
Summary: In this study, the structural, magnetic, and electrical magnetotransport properties of 24 and 51 nm thick B20-RhSi thin films grown by magnetron sputtering were investigated. The films exhibited a nonmagnetic ground state and metallic behavior. It was confirmed that the temperature-dependent electrical resistivity is governed by electron-phonon scattering. The ability to grow textured-epitaxial thin films of nonmagnetic B20 chiral topological semimetals is an important step toward designing chiraltronic devices with novel functionalities.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Luca Tomarchio, Sen Mou, Lorenzo Mosesso, Anastasios Markou, Edouard Lesne, Claudia Felser, Stefano Lupi
Summary: In this paper, we investigate the terahertz emission from thin films of the magnetic topological nodal semimetal Co2MnGa when excited by femtosecond optical pulses. We identify multiple THz generation mechanisms, including a photon-drag effect induced by radiation pressure and a photovoltaic effect from the topological surface states of CMG. This interplay between generation mechanisms highlights the potential of Co2MnGa topological nodal semimetals for THz emitter devices.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Physics, Multidisciplinary
David R. Saykin, Camron Farhang, Erik D. Kountz, Dong Chen, Brenden R. Ortiz, Chandra Shekhar, Claudia Felser, Stephen D. Wilson, Ronny Thomale, Jing Xia, Aharon Kapitulnik
Summary: This study reports high-resolution polar Kerr effect measurements on CsV3Sb5 single crystals to search for evidence of spontaneous time-reversal symmetry breaking below the charge-order transition. Utilizing two different versions of zero-area loop Sagnac interferometers operating at 1550 nm wavelength, the researchers found no observable Kerr effect within the noise floor limit. Simultaneous coherent reflection ratio measurements confirmed the sharpness of the charge-order transition, suggesting that time-reversal symmetry is unlikely to be broken in the charge ordered state in CsV3Sb5.
PHYSICAL REVIEW LETTERS
(2023)
Review
Nanoscience & Nanotechnology
Georgios Varnavides, Amir Yacoby, Claudia Felser, Prineha Narang
Summary: As high-quality single-crystal materials used in electronic devices reach smaller scales, charge-transport phenomena lead to inhomogeneous spatial signatures with significant effects on material properties. These signatures, including spatially varying dissipation and interface resistance, are crucial for device control. This Review examines the inhomogeneous charge flow signatures in conductors, focusing on electron hydrodynamics, where electrons exhibit strong interactions and flow collectively like fluids. Recent experimental advances and theoretical frameworks are discussed, along with new charge-transport phenomena introduced by crystal symmetry in materials.
NATURE REVIEWS MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Irian Sanchez-Ramirez, Maia G. Vergniory, Claudia Felser, Fernando de Juan
Summary: Among the quasi-one-dimensional transition metal tetrachalcogenides (MSe4)nI (M = Nb,Ta), the n = 3 compounds exhibit structural transitions with puzzling transport behavior instead of charge density waves. Recent discovery of a metallic polytype of (TaSe4)3I with coexisting ferromagnetism and superconductivity at low temperature challenges previous reports. In this study, ab initio and tight-binding band-structure calculations are used to explain the observed transport gaps and clarify the controversy regarding ARPES and optical conductivity experiments. The effect of small extrinsic hole doping and its implications for magnetism and superconductivity are also discussed.
Article
Materials Science, Multidisciplinary
Lun-Hui Hu, Chunyu Guo, Yan Sun, Claudia Felser, Luis Elcoro, Philip J. W. Moll, Chao-Xing Liu, Andrei Bernevig
Summary: In this study, a hierarchical structure of quasisymmetries and their corresponding nodal structures in the chiral crystal material CoSi are revealed through two different approaches of perturbation expansions. Quasisymmetries are found to play a crucial role in the physical responses of the system and can protect the existence of nodal planes.
Article
Materials Science, Multidisciplinary
Eleanor F. Scott, Katherine A. Schlaak, Poulomi Chakraborty, Chenguang Fu, Satya N. Guin, Safa Khodabakhsh, Ashley E. Paz Y. Puente, Claudia Felser, Brian Skinner, Sarah J. Watzman
Summary: In this study, it was discovered that polycrystalline NbP exhibits a large Nernst effect and a large magneto-Seebeck effect simultaneously, which is rarely observed in a single material at the same temperature. Through doping, the temperature dependence of these magnetothermoelectric effects can be altered, providing a potential tuning mechanism for device applications.
Article
Engineering, Electrical & Electronic
Ryotaro Okabe, Mingda Li, Yuma Iwasaki, Nicolas Regnault, Claudia Felser, Masafumi Shirai, Alexander Kovacs, Thomas Schrefl, Atsufumi Hirohata
Summary: This letter summarizes the recent development of using artificial intelligence and machine learning in the search for magnetic materials, and briefly introduces the approaches used in materials discovery. The authors also provide a flowchart to assist in selecting the appropriate methods for material search. The letter also covers the authors' recent research activities in magnetism and quantum materials.
IEEE MAGNETICS LETTERS
(2023)
